On Wed, Dec 09, 2015 at 04:20:10PM -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()
Signed-off-by: Rob Clark robdclark@gmail.com
drivers/gpu/drm/drm_dp_helper.c | 60 ++++++++++++++++++++++++++++++++++------- include/drm/drmP.h | 10 ++++++- 2 files changed, 59 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 76e08dc..3f27cc9 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -159,6 +159,44 @@ 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_DPCD("%s: req=0x%02x, address=0x%05x, size=%zu\n", aux->name,
msg->request, msg->address, msg->size);- if (unlikely(drm_debug & DRM_UT_DPCD)) {
switch (msg->request & ~DP_AUX_I2C_MOT) {case DP_AUX_NATIVE_WRITE:case DP_AUX_I2C_WRITE:
Missing DP_AUX_I2C_WRITE_STATUS_UPDATE on purpose?
print_hex_dump(KERN_DEBUG, "DPCD: ", DUMP_PREFIX_OFFSET,16, 1, msg->buffer, msg->size, false);
i2c != dpcd
So might be it should be called DRM_UT_AUX etc.
break;default:break;}- }
- ret = aux->transfer(aux, msg);
- DRM_DEBUG_DPCD("%s: reply=0x%02x, size=%zd\n", aux->name, msg->reply, ret);
I was thinking the reply might contain random garbage on error, but at least we memset the whole thing to zero initially, so I guess it ought to be good enough.
- if (unlikely(drm_debug & DRM_UT_DPCD) && (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 */
/** @@ -196,7 +234,7 @@ 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);@@ -212,16 +250,18 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, goto unlock;
case DP_AUX_NATIVE_REPLY_NACK:
DRM_DEBUG_DPCD("native nack (result=%d, size=%zu)\n", err, msg.size); err = -EIO; goto unlock;case DP_AUX_NATIVE_REPLY_DEFER:
DRM_DEBUG_DPCD("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: @@ -550,12 +590,12 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) WARN_ON(!mutex_is_locked(&aux->hw_mutex));
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_DPCD("transaction failed: %d\n", ret); return ret;@@ -569,11 +609,11 @@ 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_DPCD("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_DPCD("native defer\n"); /* * We could check for I2C bit rate capabilities and if * available adjust this interval. We could also be@@ -602,12 +642,12 @@ 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_DPCD("I2C nack (result=%d, size=%zu\n", ret, msg->size);
^
Might as well add the missing parenthesis while touching this. And yes, it was me who messed it up originally.
aux->i2c_nack_count++; return -EREMOTEIO; case DP_AUX_I2C_REPLY_DEFER:
DRM_DEBUG_KMS("I2C defer\n");
DRM_DEBUG_DPCD("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@@ -626,7 +666,7 @@ 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;
}
@@ -654,7 +694,7 @@ 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_DPCD("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 0a271ca..ac4d622 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -110,6 +110,8 @@ struct dma_buf_attachment;
- VBL: used for verbose debug message in the vblank code
This is the category used by the DRM_DEBUG_VBL() macro.
- DPCD: used to log (displayport) DPCD messages
- Enabling verbose debug messages is done through the drm.debug parameter,
- each category being enabled by a bit.
@@ -117,7 +119,7 @@ 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 +131,7 @@ struct dma_buf_attachment; #define DRM_UT_PRIME 0x08 #define DRM_UT_ATOMIC 0x10 #define DRM_UT_VBL 0x20 +#define DRM_UT_DPCD 0x40
extern __printf(2, 3) void drm_ut_debug_printk(const char *function_name, @@ -226,6 +229,11 @@ 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_DPCD(fmt, args...) \
- do { \
if (unlikely(drm_debug & DRM_UT_DPCD)) \drm_ut_debug_printk(__func__, fmt, ##args); \- } while (0)
/*@}*/
-- 2.5.0
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