1) don't let other threads trying to bang on aux channel interrupt the defer timeout/logic 2) don't let other threads interrupt the i2c over aux logic
Technically, according to people who actually have the DP spec, this should not be required. In practice, it makes some troublesome Dell monitor (and perhaps others) work, so probably a case of "It's compliant if it works with windows" on the hw vendor's part..
v2: rebased to come before DPCD/AUX logging patch for easier backport to stable branches.
Reported-by: Dave Wysochanski dwysocha@redhat.com Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1274157 Cc: stable@vger.kernel.org Signed-off-by: Rob Clark robdclark@gmail.com --- drivers/gpu/drm/drm_dp_helper.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 7d58f59..df64ed1 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -179,7 +179,7 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, { struct drm_dp_aux_msg msg; unsigned int retry; - int err; + int err = 0;
memset(&msg, 0, sizeof(msg)); msg.address = offset; @@ -187,6 +187,8 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, msg.buffer = buffer; msg.size = size;
+ mutex_lock(&aux->hw_mutex); + /* * The specification doesn't give any recommendation on how often to * retry native transactions. We used to retry 7 times like for @@ -195,25 +197,24 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, */ for (retry = 0; retry < 32; retry++) {
- mutex_lock(&aux->hw_mutex); err = aux->transfer(aux, &msg); - mutex_unlock(&aux->hw_mutex); if (err < 0) { if (err == -EBUSY) continue;
- return err; + goto unlock; }
switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) { case DP_AUX_NATIVE_REPLY_ACK: if (err < size) - return -EPROTO; - return err; + err = -EPROTO; + goto unlock;
case DP_AUX_NATIVE_REPLY_NACK: - return -EIO; + err = -EIO; + goto unlock;
case DP_AUX_NATIVE_REPLY_DEFER: usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); @@ -222,7 +223,11 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, }
DRM_DEBUG_KMS("too many retries, giving up\n"); - return -EIO; + err = -EIO; + +unlock: + mutex_unlock(&aux->hw_mutex); + return err; }
/** @@ -544,9 +549,7 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) int max_retries = max(7, drm_dp_i2c_retry_count(msg, dp_aux_i2c_speed_khz));
for (retry = 0, defer_i2c = 0; retry < (max_retries + defer_i2c); retry++) { - mutex_lock(&aux->hw_mutex); ret = aux->transfer(aux, msg); - mutex_unlock(&aux->hw_mutex); if (ret < 0) { if (ret == -EBUSY) continue; @@ -685,6 +688,8 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
memset(&msg, 0, sizeof(msg));
+ mutex_lock(&aux->hw_mutex); + for (i = 0; i < num; i++) { msg.address = msgs[i].addr; drm_dp_i2c_msg_set_request(&msg, &msgs[i]); @@ -739,6 +744,8 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, msg.size = 0; (void)drm_dp_i2c_do_msg(aux, &msg);
+ mutex_unlock(&aux->hw_mutex); + return err; }
Add a new drm_debug bit for turning on DPCD logging, to aid debugging with troublesome monitors.
v2: don't try to hexdump the universe if driver returns -errno, and change the "too many retries" traces to DRM_ERROR() v3: rename to more generic "AUX" instead of DP specific DPCD, add DP_AUX_I2C_WRITE_STATUS_UPDATE
Signed-off-by: Rob Clark robdclark@gmail.com --- drivers/gpu/drm/drm_dp_helper.c | 62 +++++++++++++++++++++++++++++++++-------- include/drm/drmP.h | 8 +++++- 2 files changed, 58 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index df64ed1..3ef35fd 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -160,6 +160,45 @@ int drm_dp_bw_code_to_link_rate(u8 link_bw) } EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate);
+static ssize_t aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) +{ + ssize_t ret; + + DRM_DEBUG_AUX("%s: req=0x%02x, address=0x%05x, size=%zu\n", aux->name, + msg->request, msg->address, msg->size); + + if (unlikely(drm_debug & DRM_UT_AUX)) { + switch (msg->request & ~DP_AUX_I2C_MOT) { + case DP_AUX_NATIVE_WRITE: + case DP_AUX_I2C_WRITE: + case DP_AUX_I2C_WRITE_STATUS_UPDATE: + print_hex_dump(KERN_DEBUG, "DPCD: ", DUMP_PREFIX_OFFSET, + 16, 1, msg->buffer, msg->size, false); + break; + default: + break; + } + } + + ret = aux->transfer(aux, msg); + + DRM_DEBUG_AUX("%s: reply=0x%02x, size=%zd\n", aux->name, msg->reply, ret); + + if (unlikely(drm_debug & DRM_UT_AUX) && (ret > 0)) { + switch (msg->request & ~DP_AUX_I2C_MOT) { + case DP_AUX_NATIVE_READ: + case DP_AUX_I2C_READ: + print_hex_dump(KERN_DEBUG, "DPCD: ", DUMP_PREFIX_OFFSET, + 16, 1, msg->buffer, ret, false); + break; + default: + break; + } + } + + return ret; +} + #define AUX_RETRY_INTERVAL 500 /* us */
/** @@ -197,7 +236,7 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, */ for (retry = 0; retry < 32; retry++) {
- err = aux->transfer(aux, &msg); + err = aux_transfer(aux, &msg); if (err < 0) { if (err == -EBUSY) continue; @@ -205,7 +244,6 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, goto unlock; }
- switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) { case DP_AUX_NATIVE_REPLY_ACK: if (err < size) @@ -213,16 +251,18 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, goto unlock;
case DP_AUX_NATIVE_REPLY_NACK: + DRM_DEBUG_AUX("native nack (result=%d, size=%zu)\n", err, msg.size); err = -EIO; goto unlock;
case DP_AUX_NATIVE_REPLY_DEFER: + DRM_DEBUG_AUX("native defer\n"); usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); break; } }
- DRM_DEBUG_KMS("too many retries, giving up\n"); + DRM_ERROR("DPCD: too many retries, giving up!\n"); err = -EIO;
unlock: @@ -549,12 +589,12 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) int max_retries = max(7, drm_dp_i2c_retry_count(msg, dp_aux_i2c_speed_khz));
for (retry = 0, defer_i2c = 0; retry < (max_retries + defer_i2c); retry++) { - ret = aux->transfer(aux, msg); + ret = aux_transfer(aux, msg); if (ret < 0) { if (ret == -EBUSY) continue;
- DRM_DEBUG_KMS("transaction failed: %d\n", ret); + DRM_DEBUG_AUX("transaction failed: %d\n", ret); return ret; }
@@ -568,11 +608,11 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) break;
case DP_AUX_NATIVE_REPLY_NACK: - DRM_DEBUG_KMS("native nack (result=%d, size=%zu)\n", ret, msg->size); + DRM_DEBUG_AUX("native nack (result=%d, size=%zu)\n", ret, msg->size); return -EREMOTEIO;
case DP_AUX_NATIVE_REPLY_DEFER: - DRM_DEBUG_KMS("native defer\n"); + DRM_DEBUG_AUX("native defer\n"); /* * We could check for I2C bit rate capabilities and if * available adjust this interval. We could also be @@ -601,12 +641,12 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) return ret;
case DP_AUX_I2C_REPLY_NACK: - DRM_DEBUG_KMS("I2C nack (result=%d, size=%zu\n", ret, msg->size); + DRM_DEBUG_AUX("I2C nack (result=%d, size=%zu)\n", ret, msg->size); aux->i2c_nack_count++; return -EREMOTEIO;
case DP_AUX_I2C_REPLY_DEFER: - DRM_DEBUG_KMS("I2C defer\n"); + DRM_DEBUG_AUX("I2C defer\n"); /* DP Compliance Test 4.2.2.5 Requirement: * Must have at least 7 retries for I2C defers on the * transaction to pass this test @@ -625,7 +665,7 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) } }
- DRM_DEBUG_KMS("too many retries, giving up\n"); + DRM_ERROR("I2C: too many retries, giving up\n"); return -EREMOTEIO; }
@@ -653,7 +693,7 @@ static int drm_dp_i2c_drain_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *o return err == 0 ? -EPROTO : err;
if (err < msg.size && err < ret) { - DRM_DEBUG_KMS("Partial I2C reply: requested %zu bytes got %d bytes\n", + DRM_DEBUG_AUX("Partial I2C reply: requested %zu bytes got %d bytes\n", msg.size, err); ret = err; } diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 3c8422c..cc524b5 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -117,7 +117,7 @@ struct dma_buf_attachment; * drm.debug=0x2 will enable DRIVER messages * drm.debug=0x3 will enable CORE and DRIVER messages * ... - * drm.debug=0x3f will enable all messages + * drm.debug=0x7f will enable all messages * * An interesting feature is that it's possible to enable verbose logging at * run-time by echoing the debug value in its sysfs node: @@ -129,6 +129,7 @@ struct dma_buf_attachment; #define DRM_UT_PRIME 0x08 #define DRM_UT_ATOMIC 0x10 #define DRM_UT_VBL 0x20 +#define DRM_UT_AUX 0x40
extern __printf(2, 3) void drm_ut_debug_printk(const char *function_name, @@ -226,6 +227,11 @@ void drm_err(const char *format, ...); if (unlikely(drm_debug & DRM_UT_VBL)) \ drm_ut_debug_printk(__func__, fmt, ##args); \ } while (0) +#define DRM_DEBUG_AUX(fmt, args...) \ + do { \ + if (unlikely(drm_debug & DRM_UT_AUX)) \ + drm_ut_debug_printk(__func__, fmt, ##args); \ + } while (0)
/*@}*/
On Thu, Feb 25, 2016 at 04:15:06PM -0500, Rob Clark wrote:
Add a new drm_debug bit for turning on DPCD logging, to aid debugging with troublesome monitors.
v2: don't try to hexdump the universe if driver returns -errno, and change the "too many retries" traces to DRM_ERROR() v3: rename to more generic "AUX" instead of DP specific DPCD, add DP_AUX_I2C_WRITE_STATUS_UPDATE
Signed-off-by: Rob Clark robdclark@gmail.com
drivers/gpu/drm/drm_dp_helper.c | 62 +++++++++++++++++++++++++++++++++-------- include/drm/drmP.h | 8 +++++- 2 files changed, 58 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index df64ed1..3ef35fd 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -160,6 +160,45 @@ int drm_dp_bw_code_to_link_rate(u8 link_bw) } EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate);
+static ssize_t aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) +{
- ssize_t ret;
- DRM_DEBUG_AUX("%s: req=0x%02x, address=0x%05x, size=%zu\n", aux->name,
msg->request, msg->address, msg->size);
Bunch of stuff doesn't seem to be indented quite right in this patch. This being one of them.
- if (unlikely(drm_debug & DRM_UT_AUX)) {
switch (msg->request & ~DP_AUX_I2C_MOT) {case DP_AUX_NATIVE_WRITE:case DP_AUX_I2C_WRITE:case DP_AUX_I2C_WRITE_STATUS_UPDATE:print_hex_dump(KERN_DEBUG, "DPCD: ", DUMP_PREFIX_OFFSET,16, 1, msg->buffer, msg->size, false);
That shouldn't say "DPCD", at least for i2c.
break;default:break;}- }
- ret = aux->transfer(aux, msg);
- DRM_DEBUG_AUX("%s: reply=0x%02x, size=%zd\n", aux->name, msg->reply, ret);
- if (unlikely(drm_debug & DRM_UT_AUX) && (ret > 0)) {
switch (msg->request & ~DP_AUX_I2C_MOT) {case DP_AUX_NATIVE_READ:case DP_AUX_I2C_READ:print_hex_dump(KERN_DEBUG, "DPCD: ", DUMP_PREFIX_OFFSET,16, 1, msg->buffer, ret, false);
ditto
Otherwise looks all right.
break;default:break;}- }
- return ret;
+}
#define AUX_RETRY_INTERVAL 500 /* us */
/** @@ -197,7 +236,7 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, */ for (retry = 0; retry < 32; retry++) {
err = aux->transfer(aux, &msg);
err = aux_transfer(aux, &msg);@@ -205,7 +244,6 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, goto unlock; }
- switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) { case DP_AUX_NATIVE_REPLY_ACK: if (err < size)
@@ -213,16 +251,18 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, goto unlock;
case DP_AUX_NATIVE_REPLY_NACK:
DRM_DEBUG_AUX("native nack (result=%d, size=%zu)\n", err, msg.size); err = -EIO; goto unlock;case DP_AUX_NATIVE_REPLY_DEFER:
DRM_DEBUG_AUX("native defer\n"); usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); break;} }
- DRM_DEBUG_KMS("too many retries, giving up\n");
- DRM_ERROR("DPCD: too many retries, giving up!\n"); err = -EIO;
unlock: @@ -549,12 +589,12 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) int max_retries = max(7, drm_dp_i2c_retry_count(msg, dp_aux_i2c_speed_khz));
for (retry = 0, defer_i2c = 0; retry < (max_retries + defer_i2c); retry++) {
ret = aux->transfer(aux, msg);
ret = aux_transfer(aux, msg);
DRM_DEBUG_KMS("transaction failed: %d\n", ret);
DRM_DEBUG_AUX("transaction failed: %d\n", ret); return ret;@@ -568,11 +608,11 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) break;
case DP_AUX_NATIVE_REPLY_NACK:
DRM_DEBUG_KMS("native nack (result=%d, size=%zu)\n", ret, msg->size);
DRM_DEBUG_AUX("native nack (result=%d, size=%zu)\n", ret, msg->size); return -EREMOTEIO;case DP_AUX_NATIVE_REPLY_DEFER:
DRM_DEBUG_KMS("native defer\n");
DRM_DEBUG_AUX("native defer\n"); /* * We could check for I2C bit rate capabilities and if * available adjust this interval. We could also be@@ -601,12 +641,12 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) return ret;
case DP_AUX_I2C_REPLY_NACK:
DRM_DEBUG_KMS("I2C nack (result=%d, size=%zu\n", ret, msg->size);
DRM_DEBUG_AUX("I2C nack (result=%d, size=%zu)\n", ret, msg->size); aux->i2c_nack_count++; return -EREMOTEIO;case DP_AUX_I2C_REPLY_DEFER:
DRM_DEBUG_KMS("I2C defer\n");
DRM_DEBUG_AUX("I2C defer\n"); /* DP Compliance Test 4.2.2.5 Requirement: * Must have at least 7 retries for I2C defers on the * transaction to pass this test@@ -625,7 +665,7 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) } }
- DRM_DEBUG_KMS("too many retries, giving up\n");
- DRM_ERROR("I2C: too many retries, giving up\n"); return -EREMOTEIO;
}
@@ -653,7 +693,7 @@ static int drm_dp_i2c_drain_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *o return err == 0 ? -EPROTO : err;
if (err < msg.size && err < ret) {
DRM_DEBUG_KMS("Partial I2C reply: requested %zu bytes got %d bytes\n",
DRM_DEBUG_AUX("Partial I2C reply: requested %zu bytes got %d bytes\n", msg.size, err); ret = err;diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 3c8422c..cc524b5 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -117,7 +117,7 @@ struct dma_buf_attachment;
- drm.debug=0x2 will enable DRIVER messages
- drm.debug=0x3 will enable CORE and DRIVER messages
- ...
- drm.debug=0x3f will enable all messages
- drm.debug=0x7f will enable all messages
- An interesting feature is that it's possible to enable verbose logging at
- run-time by echoing the debug value in its sysfs node:
@@ -129,6 +129,7 @@ struct dma_buf_attachment; #define DRM_UT_PRIME 0x08 #define DRM_UT_ATOMIC 0x10 #define DRM_UT_VBL 0x20 +#define DRM_UT_AUX 0x40
extern __printf(2, 3) void drm_ut_debug_printk(const char *function_name, @@ -226,6 +227,11 @@ void drm_err(const char *format, ...); if (unlikely(drm_debug & DRM_UT_VBL)) \ drm_ut_debug_printk(__func__, fmt, ##args); \ } while (0) +#define DRM_DEBUG_AUX(fmt, args...) \
- do { \
if (unlikely(drm_debug & DRM_UT_AUX)) \drm_ut_debug_printk(__func__, fmt, ##args); \- } while (0)
/*@}*/
-- 2.5.0
On Thu, 2016-02-25 at 16:15 -0500, Rob Clark wrote:
Add a new drm_debug bit for turning on DPCD logging, to aid debugging with troublesome monitors.
v2: don't try to hexdump the universe if driver returns -errno, and change the "too many retries" traces to DRM_ERROR() v3: rename to more generic "AUX" instead of DP specific DPCD, add DP_AUX_I2C_WRITE_STATUS_UPDATE
Signed-off-by: Rob Clark robdclark@gmail.com
I used the rebased version of this after Ville pointed me to it for remote debugging some odd adaptor behavior. It'd be quite useful imo, so: Acked-by: Imre Deak imre.deak@intel.com
drivers/gpu/drm/drm_dp_helper.c | 62 +++++++++++++++++++++++++++++++++-------- include/drm/drmP.h | 8 +++++- 2 files changed, 58 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index df64ed1..3ef35fd 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -160,6 +160,45 @@ int drm_dp_bw_code_to_link_rate(u8 link_bw) } EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate); +static ssize_t aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) +{
- ssize_t ret;
- DRM_DEBUG_AUX("%s: req=0x%02x, address=0x%05x, size=%zu\n", aux->name,
msg->request, msg->address, msg->size);- if (unlikely(drm_debug & DRM_UT_AUX)) {
switch (msg->request & ~DP_AUX_I2C_MOT) {case DP_AUX_NATIVE_WRITE:case DP_AUX_I2C_WRITE:case DP_AUX_I2C_WRITE_STATUS_UPDATE:print_hex_dump(KERN_DEBUG, "DPCD: ", DUMP_PREFIX_OFFSET,16, 1, msg->buffer, msg->size, false);break;default:break;}- }
- ret = aux->transfer(aux, msg);
- DRM_DEBUG_AUX("%s: reply=0x%02x, size=%zd\n", aux->name, msg->reply, ret);
- if (unlikely(drm_debug & DRM_UT_AUX) && (ret > 0)) {
switch (msg->request & ~DP_AUX_I2C_MOT) {case DP_AUX_NATIVE_READ:case DP_AUX_I2C_READ:print_hex_dump(KERN_DEBUG, "DPCD: ", DUMP_PREFIX_OFFSET,16, 1, msg->buffer, ret, false);break;default:break;}- }
- return ret;
+}
#define AUX_RETRY_INTERVAL 500 /* us */ /** @@ -197,7 +236,7 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, */ for (retry = 0; retry < 32; retry++) {
err = aux->transfer(aux, &msg);
err = aux_transfer(aux, &msg);if (err < 0) { if (err == -EBUSY) continue; @@ -205,7 +244,6 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, goto unlock; }
switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) { case DP_AUX_NATIVE_REPLY_ACK: if (err < size) @@ -213,16 +251,18 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, goto unlock; case DP_AUX_NATIVE_REPLY_NACK:
DRM_DEBUG_AUX("native nack (result=%d, size=%zu)\n", err, msg.size);err = -EIO; goto unlock; case DP_AUX_NATIVE_REPLY_DEFER:
DRM_DEBUG_AUX("native defer\n");usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); break; } }
- DRM_DEBUG_KMS("too many retries, giving up\n");
- DRM_ERROR("DPCD: too many retries, giving up!\n");
err = -EIO; unlock: @@ -549,12 +589,12 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) int max_retries = max(7, drm_dp_i2c_retry_count(msg, dp_aux_i2c_speed_khz)); for (retry = 0, defer_i2c = 0; retry < (max_retries + defer_i2c); retry++) {
ret = aux->transfer(aux, msg);
ret = aux_transfer(aux, msg);if (ret < 0) { if (ret == -EBUSY) continue;
DRM_DEBUG_KMS("transaction failed: %d\n", ret);
DRM_DEBUG_AUX("transaction failed: %d\n", ret);return ret; } @@ -568,11 +608,11 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) break; case DP_AUX_NATIVE_REPLY_NACK:
DRM_DEBUG_KMS("native nack (result=%d, size=%zu)\n", ret, msg->size);
DRM_DEBUG_AUX("native nack (result=%d, size=%zu)\n", ret, msg->size);return -EREMOTEIO; case DP_AUX_NATIVE_REPLY_DEFER:
DRM_DEBUG_KMS("native defer\n");
DRM_DEBUG_AUX("native defer\n");/* * We could check for I2C bit rate capabilities and if * available adjust this interval. We could also be @@ -601,12 +641,12 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) return ret; case DP_AUX_I2C_REPLY_NACK:
DRM_DEBUG_KMS("I2C nack (result=%d, size=%zu\n", ret, msg->size);
DRM_DEBUG_AUX("I2C nack (result=%d, size=%zu)\n", ret, msg->size);aux->i2c_nack_count++; return -EREMOTEIO; case DP_AUX_I2C_REPLY_DEFER:
DRM_DEBUG_KMS("I2C defer\n");
DRM_DEBUG_AUX("I2C defer\n");/* DP Compliance Test 4.2.2.5 Requirement: * Must have at least 7 retries for I2C defers on the * transaction to pass this test @@ -625,7 +665,7 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) } }
- DRM_DEBUG_KMS("too many retries, giving up\n");
- DRM_ERROR("I2C: too many retries, giving up\n");
return -EREMOTEIO; } @@ -653,7 +693,7 @@ static int drm_dp_i2c_drain_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *o return err == 0 ? -EPROTO : err; if (err < msg.size && err < ret) {
DRM_DEBUG_KMS("Partial I2C reply: requested %zu bytes got %d bytes\n",
DRM_DEBUG_AUX("Partial I2C reply: requested %zu bytes got %d bytes\n",msg.size, err); ret = err; } diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 3c8422c..cc524b5 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -117,7 +117,7 @@ struct dma_buf_attachment; * drm.debug=0x2 will enable DRIVER messages * drm.debug=0x3 will enable CORE and DRIVER messages * ...
- drm.debug=0x3f will enable all messages
- drm.debug=0x7f will enable all messages
* * An interesting feature is that it's possible to enable verbose logging at * run-time by echoing the debug value in its sysfs node: @@ -129,6 +129,7 @@ struct dma_buf_attachment; #define DRM_UT_PRIME 0x08 #define DRM_UT_ATOMIC 0x10 #define DRM_UT_VBL 0x20 +#define DRM_UT_AUX 0x40 extern __printf(2, 3) void drm_ut_debug_printk(const char *function_name, @@ -226,6 +227,11 @@ void drm_err(const char *format, ...); if (unlikely(drm_debug & DRM_UT_VBL)) \ drm_ut_debug_printk(__func__, fmt, ##args); \ } while (0) +#define DRM_DEBUG_AUX(fmt, args...) \
- do { \
if (unlikely(drm_debug & DRM_UT_AUX)) \drm_ut_debug_printk(__func__, fmt, ##args); \- } while (0)
/*@}*/
On Wed, Dec 21, 2016 at 3:41 PM, Imre Deak imre.deak@intel.com wrote:
On Thu, 2016-02-25 at 16:15 -0500, Rob Clark wrote:
Add a new drm_debug bit for turning on DPCD logging, to aid debugging with troublesome monitors.
v2: don't try to hexdump the universe if driver returns -errno, and change the "too many retries" traces to DRM_ERROR() v3: rename to more generic "AUX" instead of DP specific DPCD, add DP_AUX_I2C_WRITE_STATUS_UPDATE
Signed-off-by: Rob Clark robdclark@gmail.com
I used the rebased version of this after Ville pointed me to it for remote debugging some odd adaptor behavior. It'd be quite useful imo, so: Acked-by: Imre Deak imre.deak@intel.com
tbh I completely forgot about this patch.. mind posting the rebased version (or push to a git tree somewhere)? IIRC there were just some minor cosmetic things to fix up, probably worth doing that before I forget about it again..
BR, -R
drivers/gpu/drm/drm_dp_helper.c | 62 +++++++++++++++++++++++++++++++++-------- include/drm/drmP.h | 8 +++++- 2 files changed, 58 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index df64ed1..3ef35fd 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -160,6 +160,45 @@ int drm_dp_bw_code_to_link_rate(u8 link_bw) } EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate);
+static ssize_t aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) +{
ssize_t ret;DRM_DEBUG_AUX("%s: req=0x%02x, address=0x%05x, size=%zu\n", aux->name,msg->request, msg->address, msg->size);if (unlikely(drm_debug & DRM_UT_AUX)) {switch (msg->request & ~DP_AUX_I2C_MOT) {case DP_AUX_NATIVE_WRITE:case DP_AUX_I2C_WRITE:case DP_AUX_I2C_WRITE_STATUS_UPDATE:print_hex_dump(KERN_DEBUG, "DPCD: ", DUMP_PREFIX_OFFSET,16, 1, msg->buffer, msg->size, false);break;default:break;}}ret = aux->transfer(aux, msg);DRM_DEBUG_AUX("%s: reply=0x%02x, size=%zd\n", aux->name, msg->reply, ret);if (unlikely(drm_debug & DRM_UT_AUX) && (ret > 0)) {switch (msg->request & ~DP_AUX_I2C_MOT) {case DP_AUX_NATIVE_READ:case DP_AUX_I2C_READ:print_hex_dump(KERN_DEBUG, "DPCD: ", DUMP_PREFIX_OFFSET,16, 1, msg->buffer, ret, false);break;default:break;}}return ret;+}
#define AUX_RETRY_INTERVAL 500 /* us */
/** @@ -197,7 +236,7 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, */ for (retry = 0; retry < 32; retry++) {
err = aux->transfer(aux, &msg);
err = aux_transfer(aux, &msg); if (err < 0) { if (err == -EBUSY) continue;@@ -205,7 +244,6 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, goto unlock; }
switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) { case DP_AUX_NATIVE_REPLY_ACK: if (err < size)@@ -213,16 +251,18 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, goto unlock;
case DP_AUX_NATIVE_REPLY_NACK:
DRM_DEBUG_AUX("native nack (result=%d, size=%zu)\n", err, msg.size); err = -EIO; goto unlock; case DP_AUX_NATIVE_REPLY_DEFER:DRM_DEBUG_AUX("native defer\n"); usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); break; } }
DRM_DEBUG_KMS("too many retries, giving up\n");
DRM_ERROR("DPCD: too many retries, giving up!\n"); err = -EIO;unlock: @@ -549,12 +589,12 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) int max_retries = max(7, drm_dp_i2c_retry_count(msg, dp_aux_i2c_speed_khz));
for (retry = 0, defer_i2c = 0; retry < (max_retries + defer_i2c); retry++) {
ret = aux->transfer(aux, msg);
ret = aux_transfer(aux, msg); if (ret < 0) { if (ret == -EBUSY) continue;
DRM_DEBUG_KMS("transaction failed: %d\n", ret);
DRM_DEBUG_AUX("transaction failed: %d\n", ret); return ret; }@@ -568,11 +608,11 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) break;
case DP_AUX_NATIVE_REPLY_NACK:
DRM_DEBUG_KMS("native nack (result=%d, size=%zu)\n", ret, msg->size);
DRM_DEBUG_AUX("native nack (result=%d, size=%zu)\n", ret, msg->size); return -EREMOTEIO; case DP_AUX_NATIVE_REPLY_DEFER:
DRM_DEBUG_KMS("native defer\n");
DRM_DEBUG_AUX("native defer\n"); /* * We could check for I2C bit rate capabilities and if * available adjust this interval. We could also be@@ -601,12 +641,12 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) return ret;
case DP_AUX_I2C_REPLY_NACK:
DRM_DEBUG_KMS("I2C nack (result=%d, size=%zu\n", ret, msg->size);
DRM_DEBUG_AUX("I2C nack (result=%d, size=%zu)\n", ret, msg->size); aux->i2c_nack_count++; return -EREMOTEIO; case DP_AUX_I2C_REPLY_DEFER:
DRM_DEBUG_KMS("I2C defer\n");
DRM_DEBUG_AUX("I2C defer\n"); /* DP Compliance Test 4.2.2.5 Requirement: * Must have at least 7 retries for I2C defers on the * transaction to pass this test@@ -625,7 +665,7 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) } }
DRM_DEBUG_KMS("too many retries, giving up\n");
DRM_ERROR("I2C: too many retries, giving up\n"); return -EREMOTEIO;}
@@ -653,7 +693,7 @@ static int drm_dp_i2c_drain_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *o return err == 0 ? -EPROTO : err;
if (err < msg.size && err < ret) {
DRM_DEBUG_KMS("Partial I2C reply: requested %zu bytes got %d bytes\n",
DRM_DEBUG_AUX("Partial I2C reply: requested %zu bytes got %d bytes\n", msg.size, err); ret = err; }diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 3c8422c..cc524b5 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -117,7 +117,7 @@ struct dma_buf_attachment;
- drm.debug=0x2 will enable DRIVER messages
- drm.debug=0x3 will enable CORE and DRIVER messages
- ...
- drm.debug=0x3f will enable all messages
- drm.debug=0x7f will enable all messages
- An interesting feature is that it's possible to enable verbose logging at
- run-time by echoing the debug value in its sysfs node:
@@ -129,6 +129,7 @@ struct dma_buf_attachment; #define DRM_UT_PRIME 0x08 #define DRM_UT_ATOMIC 0x10 #define DRM_UT_VBL 0x20 +#define DRM_UT_AUX 0x40
extern __printf(2, 3) void drm_ut_debug_printk(const char *function_name, @@ -226,6 +227,11 @@ void drm_err(const char *format, ...); if (unlikely(drm_debug & DRM_UT_VBL)) \ drm_ut_debug_printk(__func__, fmt, ##args); \ } while (0) +#define DRM_DEBUG_AUX(fmt, args...) \
do { \if (unlikely(drm_debug & DRM_UT_AUX)) \drm_ut_debug_printk(__func__, fmt, ##args); \} while (0)/*@}*/
On Wed, Dec 21, 2016 at 05:21:18PM -0500, Rob Clark wrote:
On Wed, Dec 21, 2016 at 3:41 PM, Imre Deak imre.deak@intel.com wrote:
On Thu, 2016-02-25 at 16:15 -0500, Rob Clark wrote:
Add a new drm_debug bit for turning on DPCD logging, to aid debugging with troublesome monitors.
v2: don't try to hexdump the universe if driver returns -errno, and change the "too many retries" traces to DRM_ERROR() v3: rename to more generic "AUX" instead of DP specific DPCD, add DP_AUX_I2C_WRITE_STATUS_UPDATE
Signed-off-by: Rob Clark robdclark@gmail.com
I used the rebased version of this after Ville pointed me to it for remote debugging some odd adaptor behavior. It'd be quite useful imo, so: Acked-by: Imre Deak imre.deak@intel.com
tbh I completely forgot about this patch.. mind posting the rebased version (or push to a git tree somewhere)? IIRC there were just some minor cosmetic things to fix up, probably worth doing that before I forget about it again..
There's patches for dynamic debugging floating around, I think that'd be the more interesting approach than adding ever more magic bits that no one understands. But besides that this makes sense. -Daniel
BR, -R
drivers/gpu/drm/drm_dp_helper.c | 62 +++++++++++++++++++++++++++++++++-------- include/drm/drmP.h | 8 +++++- 2 files changed, 58 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index df64ed1..3ef35fd 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -160,6 +160,45 @@ int drm_dp_bw_code_to_link_rate(u8 link_bw) } EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate);
+static ssize_t aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) +{
ssize_t ret;DRM_DEBUG_AUX("%s: req=0x%02x, address=0x%05x, size=%zu\n", aux->name,msg->request, msg->address, msg->size);if (unlikely(drm_debug & DRM_UT_AUX)) {switch (msg->request & ~DP_AUX_I2C_MOT) {case DP_AUX_NATIVE_WRITE:case DP_AUX_I2C_WRITE:case DP_AUX_I2C_WRITE_STATUS_UPDATE:print_hex_dump(KERN_DEBUG, "DPCD: ", DUMP_PREFIX_OFFSET,16, 1, msg->buffer, msg->size, false);break;default:break;}}ret = aux->transfer(aux, msg);DRM_DEBUG_AUX("%s: reply=0x%02x, size=%zd\n", aux->name, msg->reply, ret);if (unlikely(drm_debug & DRM_UT_AUX) && (ret > 0)) {switch (msg->request & ~DP_AUX_I2C_MOT) {case DP_AUX_NATIVE_READ:case DP_AUX_I2C_READ:print_hex_dump(KERN_DEBUG, "DPCD: ", DUMP_PREFIX_OFFSET,16, 1, msg->buffer, ret, false);break;default:break;}}return ret;+}
#define AUX_RETRY_INTERVAL 500 /* us */
/** @@ -197,7 +236,7 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, */ for (retry = 0; retry < 32; retry++) {
err = aux->transfer(aux, &msg);
err = aux_transfer(aux, &msg); if (err < 0) { if (err == -EBUSY) continue;@@ -205,7 +244,6 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, goto unlock; }
switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) { case DP_AUX_NATIVE_REPLY_ACK: if (err < size)@@ -213,16 +251,18 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, goto unlock;
case DP_AUX_NATIVE_REPLY_NACK:
DRM_DEBUG_AUX("native nack (result=%d, size=%zu)\n", err, msg.size); err = -EIO; goto unlock; case DP_AUX_NATIVE_REPLY_DEFER:DRM_DEBUG_AUX("native defer\n"); usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); break; } }
DRM_DEBUG_KMS("too many retries, giving up\n");
DRM_ERROR("DPCD: too many retries, giving up!\n"); err = -EIO;unlock: @@ -549,12 +589,12 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) int max_retries = max(7, drm_dp_i2c_retry_count(msg, dp_aux_i2c_speed_khz));
for (retry = 0, defer_i2c = 0; retry < (max_retries + defer_i2c); retry++) {
ret = aux->transfer(aux, msg);
ret = aux_transfer(aux, msg); if (ret < 0) { if (ret == -EBUSY) continue;
DRM_DEBUG_KMS("transaction failed: %d\n", ret);
DRM_DEBUG_AUX("transaction failed: %d\n", ret); return ret; }@@ -568,11 +608,11 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) break;
case DP_AUX_NATIVE_REPLY_NACK:
DRM_DEBUG_KMS("native nack (result=%d, size=%zu)\n", ret, msg->size);
DRM_DEBUG_AUX("native nack (result=%d, size=%zu)\n", ret, msg->size); return -EREMOTEIO; case DP_AUX_NATIVE_REPLY_DEFER:
DRM_DEBUG_KMS("native defer\n");
DRM_DEBUG_AUX("native defer\n"); /* * We could check for I2C bit rate capabilities and if * available adjust this interval. We could also be@@ -601,12 +641,12 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) return ret;
case DP_AUX_I2C_REPLY_NACK:
DRM_DEBUG_KMS("I2C nack (result=%d, size=%zu\n", ret, msg->size);
DRM_DEBUG_AUX("I2C nack (result=%d, size=%zu)\n", ret, msg->size); aux->i2c_nack_count++; return -EREMOTEIO; case DP_AUX_I2C_REPLY_DEFER:
DRM_DEBUG_KMS("I2C defer\n");
DRM_DEBUG_AUX("I2C defer\n"); /* DP Compliance Test 4.2.2.5 Requirement: * Must have at least 7 retries for I2C defers on the * transaction to pass this test@@ -625,7 +665,7 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) } }
DRM_DEBUG_KMS("too many retries, giving up\n");
DRM_ERROR("I2C: too many retries, giving up\n"); return -EREMOTEIO;}
@@ -653,7 +693,7 @@ static int drm_dp_i2c_drain_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *o return err == 0 ? -EPROTO : err;
if (err < msg.size && err < ret) {
DRM_DEBUG_KMS("Partial I2C reply: requested %zu bytes got %d bytes\n",
DRM_DEBUG_AUX("Partial I2C reply: requested %zu bytes got %d bytes\n", msg.size, err); ret = err; }diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 3c8422c..cc524b5 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -117,7 +117,7 @@ struct dma_buf_attachment;
- drm.debug=0x2 will enable DRIVER messages
- drm.debug=0x3 will enable CORE and DRIVER messages
- ...
- drm.debug=0x3f will enable all messages
- drm.debug=0x7f will enable all messages
- An interesting feature is that it's possible to enable verbose logging at
- run-time by echoing the debug value in its sysfs node:
@@ -129,6 +129,7 @@ struct dma_buf_attachment; #define DRM_UT_PRIME 0x08 #define DRM_UT_ATOMIC 0x10 #define DRM_UT_VBL 0x20 +#define DRM_UT_AUX 0x40
extern __printf(2, 3) void drm_ut_debug_printk(const char *function_name, @@ -226,6 +227,11 @@ void drm_err(const char *format, ...); if (unlikely(drm_debug & DRM_UT_VBL)) \ drm_ut_debug_printk(__func__, fmt, ##args); \ } while (0) +#define DRM_DEBUG_AUX(fmt, args...) \
do { \if (unlikely(drm_debug & DRM_UT_AUX)) \drm_ut_debug_printk(__func__, fmt, ##args); \} while (0)/*@}*/
dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
On Thu, 2016-12-22 at 08:02 +0100, Daniel Vetter wrote:
On Wed, Dec 21, 2016 at 05:21:18PM -0500, Rob Clark wrote:
On Wed, Dec 21, 2016 at 3:41 PM, Imre Deak imre.deak@intel.com wrote:
On Thu, 2016-02-25 at 16:15 -0500, Rob Clark wrote:
Add a new drm_debug bit for turning on DPCD logging, to aid debugging with troublesome monitors.
v2: don't try to hexdump the universe if driver returns -errno, and change the "too many retries" traces to DRM_ERROR() v3: rename to more generic "AUX" instead of DP specific DPCD, add DP_AUX_I2C_WRITE_STATUS_UPDATE
Signed-off-by: Rob Clark robdclark@gmail.com
I used the rebased version of this after Ville pointed me to it for remote debugging some odd adaptor behavior. It'd be quite useful imo, so: Acked-by: Imre Deak imre.deak@intel.com
tbh I completely forgot about this patch.. mind posting the rebased version (or push to a git tree somewhere)? IIRC there were just some minor cosmetic things to fix up, probably worth doing that before I forget about it again..
There's patches for dynamic debugging floating around, I think that'd be the more interesting approach than adding ever more magic bits that no one understands. But besides that this makes sense.
Ok, although it's better than not having any way to debug and it could be converted to dyndbg with the reset. For reference: https://github.com/ideak/linux/commits/aux-debug
--Imre
-Daniel
BR, -R
drivers/gpu/drm/drm_dp_helper.c | 62 +++++++++++++++++++++++++++++++++-------- include/drm/drmP.h | 8 +++++- 2 files changed, 58 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index df64ed1..3ef35fd 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -160,6 +160,45 @@ int drm_dp_bw_code_to_link_rate(u8 link_bw) } EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate);
+static ssize_t aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) +{ + ssize_t ret;
+ DRM_DEBUG_AUX("%s: req=0x%02x, address=0x%05x, size=%zu\n", aux->name, + msg->request, msg->address, msg->size);
+ if (unlikely(drm_debug & DRM_UT_AUX)) { + switch (msg->request & ~DP_AUX_I2C_MOT) { + case DP_AUX_NATIVE_WRITE: + case DP_AUX_I2C_WRITE: + case DP_AUX_I2C_WRITE_STATUS_UPDATE: + print_hex_dump(KERN_DEBUG, "DPCD: ", DUMP_PREFIX_OFFSET, + 16, 1, msg->buffer, msg->size, false); + break; + default: + break; + } + }
+ ret = aux->transfer(aux, msg);
+ DRM_DEBUG_AUX("%s: reply=0x%02x, size=%zd\n", aux->name, msg->reply, ret);
+ if (unlikely(drm_debug & DRM_UT_AUX) && (ret > 0)) { + switch (msg->request & ~DP_AUX_I2C_MOT) { + case DP_AUX_NATIVE_READ: + case DP_AUX_I2C_READ: + print_hex_dump(KERN_DEBUG, "DPCD: ", DUMP_PREFIX_OFFSET, + 16, 1, msg->buffer, ret, false); + break; + default: + break; + } + }
+ return ret; +}
#define AUX_RETRY_INTERVAL 500 /* us */
/** @@ -197,7 +236,7 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, */ for (retry = 0; retry < 32; retry++) {
- err = aux->transfer(aux, &msg); + err = aux_transfer(aux, &msg); if (err < 0) { if (err == -EBUSY) continue; @@ -205,7 +244,6 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, goto unlock; }
switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) { case DP_AUX_NATIVE_REPLY_ACK: if (err < size) @@ -213,16 +251,18 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, goto unlock;
case DP_AUX_NATIVE_REPLY_NACK: + DRM_DEBUG_AUX("native nack (result=%d, size=%zu)\n", err, msg.size); err = -EIO; goto unlock;
case DP_AUX_NATIVE_REPLY_DEFER: + DRM_DEBUG_AUX("native defer\n"); usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); break; } }
- DRM_DEBUG_KMS("too many retries, giving up\n"); + DRM_ERROR("DPCD: too many retries, giving up!\n"); err = -EIO;
unlock: @@ -549,12 +589,12 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) int max_retries = max(7, drm_dp_i2c_retry_count(msg, dp_aux_i2c_speed_khz));
for (retry = 0, defer_i2c = 0; retry < (max_retries + defer_i2c); retry++) { - ret = aux->transfer(aux, msg); + ret = aux_transfer(aux, msg); if (ret < 0) { if (ret == -EBUSY) continue;
- DRM_DEBUG_KMS("transaction failed: %d\n", ret); + DRM_DEBUG_AUX("transaction failed: %d\n", ret); return ret; }
@@ -568,11 +608,11 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) break;
case DP_AUX_NATIVE_REPLY_NACK: - DRM_DEBUG_KMS("native nack (result=%d, size=%zu)\n", ret, msg->size); + DRM_DEBUG_AUX("native nack (result=%d, size=%zu)\n", ret, msg->size); return -EREMOTEIO;
case DP_AUX_NATIVE_REPLY_DEFER: - DRM_DEBUG_KMS("native defer\n"); + DRM_DEBUG_AUX("native defer\n"); /* * We could check for I2C bit rate capabilities and if * available adjust this interval. We could also be @@ -601,12 +641,12 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) return ret;
case DP_AUX_I2C_REPLY_NACK: - DRM_DEBUG_KMS("I2C nack (result=%d, size=%zu\n", ret, msg->size); + DRM_DEBUG_AUX("I2C nack (result=%d, size=%zu)\n", ret, msg->size); aux->i2c_nack_count++; return -EREMOTEIO;
case DP_AUX_I2C_REPLY_DEFER: - DRM_DEBUG_KMS("I2C defer\n"); + DRM_DEBUG_AUX("I2C defer\n"); /* DP Compliance Test 4.2.2.5 Requirement: * Must have at least 7 retries for I2C defers on the * transaction to pass this test @@ -625,7 +665,7 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) } }
- DRM_DEBUG_KMS("too many retries, giving up\n"); + DRM_ERROR("I2C: too many retries, giving up\n"); return -EREMOTEIO; }
@@ -653,7 +693,7 @@ static int drm_dp_i2c_drain_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *o return err == 0 ? -EPROTO : err;
if (err < msg.size && err < ret) { - DRM_DEBUG_KMS("Partial I2C reply: requested %zu bytes got %d bytes\n", + DRM_DEBUG_AUX("Partial I2C reply: requested %zu bytes got %d bytes\n", msg.size, err); ret = err; } diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 3c8422c..cc524b5 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -117,7 +117,7 @@ struct dma_buf_attachment; * drm.debug=0x2 will enable DRIVER messages * drm.debug=0x3 will enable CORE and DRIVER messages * ...
- drm.debug=0x3f will enable all messages
- drm.debug=0x7f will enable all messages
* * An interesting feature is that it's possible to enable verbose logging at * run-time by echoing the debug value in its sysfs node: @@ -129,6 +129,7 @@ struct dma_buf_attachment; #define DRM_UT_PRIME 0x08 #define DRM_UT_ATOMIC 0x10 #define DRM_UT_VBL 0x20 +#define DRM_UT_AUX 0x40
extern __printf(2, 3) void drm_ut_debug_printk(const char *function_name, @@ -226,6 +227,11 @@ void drm_err(const char *format, ...); if (unlikely(drm_debug & DRM_UT_VBL)) \ drm_ut_debug_printk(__func__, fmt, ##args); \ } while (0) +#define DRM_DEBUG_AUX(fmt, args...) \ + do { \ + if (unlikely(drm_debug & DRM_UT_AUX)) \ + drm_ut_debug_printk(__func__, fmt, ##args); \ + } while (0)
/*@}*/
dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
On Thu, Dec 22, 2016 at 2:02 AM, Daniel Vetter daniel@ffwll.ch wrote:
On Wed, Dec 21, 2016 at 05:21:18PM -0500, Rob Clark wrote:
On Wed, Dec 21, 2016 at 3:41 PM, Imre Deak imre.deak@intel.com wrote:
On Thu, 2016-02-25 at 16:15 -0500, Rob Clark wrote:
Add a new drm_debug bit for turning on DPCD logging, to aid debugging with troublesome monitors.
v2: don't try to hexdump the universe if driver returns -errno, and change the "too many retries" traces to DRM_ERROR() v3: rename to more generic "AUX" instead of DP specific DPCD, add DP_AUX_I2C_WRITE_STATUS_UPDATE
Signed-off-by: Rob Clark robdclark@gmail.com
I used the rebased version of this after Ville pointed me to it for remote debugging some odd adaptor behavior. It'd be quite useful imo, so: Acked-by: Imre Deak imre.deak@intel.com
tbh I completely forgot about this patch.. mind posting the rebased version (or push to a git tree somewhere)? IIRC there were just some minor cosmetic things to fix up, probably worth doing that before I forget about it again..
There's patches for dynamic debugging floating around, I think that'd be the more interesting approach than adding ever more magic bits that no one understands. But besides that this makes sense.
could make sense.. and by all means if someone wants to take over this patch and do something more clever, go for it..
I won't have access to a dp monitor for a couple weeks, so other than minor cosmetic tweaks there isn't much I can do.. and I mostly don't want this to fall through the cracks again.
BR, -R
-Daniel
BR, -R
drivers/gpu/drm/drm_dp_helper.c | 62 +++++++++++++++++++++++++++++++++-------- include/drm/drmP.h | 8 +++++- 2 files changed, 58 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index df64ed1..3ef35fd 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -160,6 +160,45 @@ int drm_dp_bw_code_to_link_rate(u8 link_bw) } EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate);
+static ssize_t aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) +{
ssize_t ret;DRM_DEBUG_AUX("%s: req=0x%02x, address=0x%05x, size=%zu\n", aux->name,msg->request, msg->address, msg->size);if (unlikely(drm_debug & DRM_UT_AUX)) {switch (msg->request & ~DP_AUX_I2C_MOT) {case DP_AUX_NATIVE_WRITE:case DP_AUX_I2C_WRITE:case DP_AUX_I2C_WRITE_STATUS_UPDATE:print_hex_dump(KERN_DEBUG, "DPCD: ", DUMP_PREFIX_OFFSET,16, 1, msg->buffer, msg->size, false);break;default:break;}}ret = aux->transfer(aux, msg);DRM_DEBUG_AUX("%s: reply=0x%02x, size=%zd\n", aux->name, msg->reply, ret);if (unlikely(drm_debug & DRM_UT_AUX) && (ret > 0)) {switch (msg->request & ~DP_AUX_I2C_MOT) {case DP_AUX_NATIVE_READ:case DP_AUX_I2C_READ:print_hex_dump(KERN_DEBUG, "DPCD: ", DUMP_PREFIX_OFFSET,16, 1, msg->buffer, ret, false);break;default:break;}}return ret;+}
#define AUX_RETRY_INTERVAL 500 /* us */
/** @@ -197,7 +236,7 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, */ for (retry = 0; retry < 32; retry++) {
err = aux->transfer(aux, &msg);
err = aux_transfer(aux, &msg); if (err < 0) { if (err == -EBUSY) continue;@@ -205,7 +244,6 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, goto unlock; }
switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) { case DP_AUX_NATIVE_REPLY_ACK: if (err < size)@@ -213,16 +251,18 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, goto unlock;
case DP_AUX_NATIVE_REPLY_NACK:
DRM_DEBUG_AUX("native nack (result=%d, size=%zu)\n", err, msg.size); err = -EIO; goto unlock; case DP_AUX_NATIVE_REPLY_DEFER:DRM_DEBUG_AUX("native defer\n"); usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); break; } }
DRM_DEBUG_KMS("too many retries, giving up\n");
DRM_ERROR("DPCD: too many retries, giving up!\n"); err = -EIO;unlock: @@ -549,12 +589,12 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) int max_retries = max(7, drm_dp_i2c_retry_count(msg, dp_aux_i2c_speed_khz));
for (retry = 0, defer_i2c = 0; retry < (max_retries + defer_i2c); retry++) {
ret = aux->transfer(aux, msg);
ret = aux_transfer(aux, msg); if (ret < 0) { if (ret == -EBUSY) continue;
DRM_DEBUG_KMS("transaction failed: %d\n", ret);
DRM_DEBUG_AUX("transaction failed: %d\n", ret); return ret; }@@ -568,11 +608,11 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) break;
case DP_AUX_NATIVE_REPLY_NACK:
DRM_DEBUG_KMS("native nack (result=%d, size=%zu)\n", ret, msg->size);
DRM_DEBUG_AUX("native nack (result=%d, size=%zu)\n", ret, msg->size); return -EREMOTEIO; case DP_AUX_NATIVE_REPLY_DEFER:
DRM_DEBUG_KMS("native defer\n");
DRM_DEBUG_AUX("native defer\n"); /* * We could check for I2C bit rate capabilities and if * available adjust this interval. We could also be@@ -601,12 +641,12 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) return ret;
case DP_AUX_I2C_REPLY_NACK:
DRM_DEBUG_KMS("I2C nack (result=%d, size=%zu\n", ret, msg->size);
DRM_DEBUG_AUX("I2C nack (result=%d, size=%zu)\n", ret, msg->size); aux->i2c_nack_count++; return -EREMOTEIO; case DP_AUX_I2C_REPLY_DEFER:
DRM_DEBUG_KMS("I2C defer\n");
DRM_DEBUG_AUX("I2C defer\n"); /* DP Compliance Test 4.2.2.5 Requirement: * Must have at least 7 retries for I2C defers on the * transaction to pass this test@@ -625,7 +665,7 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) } }
DRM_DEBUG_KMS("too many retries, giving up\n");
DRM_ERROR("I2C: too many retries, giving up\n"); return -EREMOTEIO;}
@@ -653,7 +693,7 @@ static int drm_dp_i2c_drain_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *o return err == 0 ? -EPROTO : err;
if (err < msg.size && err < ret) {
DRM_DEBUG_KMS("Partial I2C reply: requested %zu bytes got %d bytes\n",
DRM_DEBUG_AUX("Partial I2C reply: requested %zu bytes got %d bytes\n", msg.size, err); ret = err; }diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 3c8422c..cc524b5 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -117,7 +117,7 @@ struct dma_buf_attachment;
- drm.debug=0x2 will enable DRIVER messages
- drm.debug=0x3 will enable CORE and DRIVER messages
- ...
- drm.debug=0x3f will enable all messages
- drm.debug=0x7f will enable all messages
- An interesting feature is that it's possible to enable verbose logging at
- run-time by echoing the debug value in its sysfs node:
@@ -129,6 +129,7 @@ struct dma_buf_attachment; #define DRM_UT_PRIME 0x08 #define DRM_UT_ATOMIC 0x10 #define DRM_UT_VBL 0x20 +#define DRM_UT_AUX 0x40
extern __printf(2, 3) void drm_ut_debug_printk(const char *function_name, @@ -226,6 +227,11 @@ void drm_err(const char *format, ...); if (unlikely(drm_debug & DRM_UT_VBL)) \ drm_ut_debug_printk(__func__, fmt, ##args); \ } while (0) +#define DRM_DEBUG_AUX(fmt, args...) \
do { \if (unlikely(drm_debug & DRM_UT_AUX)) \drm_ut_debug_printk(__func__, fmt, ##args); \} while (0)/*@}*/
dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
-- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
On Thu, Feb 25, 2016 at 04:15:05PM -0500, Rob Clark wrote:
- don't let other threads trying to bang on aux channel interrupt the
defer timeout/logic 2) don't let other threads interrupt the i2c over aux logic
Technically, according to people who actually have the DP spec, this should not be required. In practice, it makes some troublesome Dell monitor (and perhaps others) work, so probably a case of "It's compliant if it works with windows" on the hw vendor's part..
v2: rebased to come before DPCD/AUX logging patch for easier backport to stable branches.
Reported-by: Dave Wysochanski dwysocha@redhat.com Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1274157 Cc: stable@vger.kernel.org Signed-off-by: Rob Clark robdclark@gmail.com
Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch
Dave, can you pls pick up?
Thanks, Daniel
drivers/gpu/drm/drm_dp_helper.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 7d58f59..df64ed1 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -179,7 +179,7 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, { struct drm_dp_aux_msg msg; unsigned int retry;
- int err;
int err = 0;
memset(&msg, 0, sizeof(msg)); msg.address = offset;
@@ -187,6 +187,8 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, msg.buffer = buffer; msg.size = size;
- mutex_lock(&aux->hw_mutex);
- /*
- The specification doesn't give any recommendation on how often to
- retry native transactions. We used to retry 7 times like for
@@ -195,25 +197,24 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, */ for (retry = 0; retry < 32; retry++) {
mutex_lock(&aux->hw_mutex);err = aux->transfer(aux, &msg);
mutex_unlock(&aux->hw_mutex);if (err < 0) { if (err == -EBUSY) continue;
return err;
goto unlock;}
switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) { case DP_AUX_NATIVE_REPLY_ACK: if (err < size)
return -EPROTO;return err;
err = -EPROTO;goto unlock;case DP_AUX_NATIVE_REPLY_NACK:
return -EIO;
err = -EIO;goto unlock;case DP_AUX_NATIVE_REPLY_DEFER: usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100);
@@ -222,7 +223,11 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, }
DRM_DEBUG_KMS("too many retries, giving up\n");
- return -EIO;
- err = -EIO;
+unlock:
- mutex_unlock(&aux->hw_mutex);
- return err;
}
/** @@ -544,9 +549,7 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) int max_retries = max(7, drm_dp_i2c_retry_count(msg, dp_aux_i2c_speed_khz));
for (retry = 0, defer_i2c = 0; retry < (max_retries + defer_i2c); retry++) {
mutex_lock(&aux->hw_mutex);mutex_unlock(&aux->hw_mutex);@@ -685,6 +688,8 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
memset(&msg, 0, sizeof(msg));
- mutex_lock(&aux->hw_mutex);
- for (i = 0; i < num; i++) { msg.address = msgs[i].addr; drm_dp_i2c_msg_set_request(&msg, &msgs[i]);
@@ -739,6 +744,8 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, msg.size = 0; (void)drm_dp_i2c_do_msg(aux, &msg);
- mutex_unlock(&aux->hw_mutex);
- return err;
}
-- 2.5.0
dri-devel@lists.freedesktop.org
-
Daniel Vetter -
Imre Deak -
Rob Clark -
Ville Syrjälä