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)
/*@}*/
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