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| author | Rodrigo Vivi <rodrigo.vivi@intel.com> | 2015-07-24 02:35:50 +0300 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2015-08-14 19:16:29 +0300 |
| commit | aabc95dcf200908993573b2019ff5210121bcba9 (patch) | |
| tree | 8925c09e52c8af69a38823d0a854271c02fcc636 | |
| parent | 621d4c76fd4ce7f648fa59a26e3eb6b2346cf873 (diff) | |
| download | linux-aabc95dcf200908993573b2019ff5210121bcba9.tar.xz | |
drm/i915: Dont -ETIMEDOUT on identical new and previous (count, crc).
By Vesa DP 1.2 spec TEST_CRC_COUNT is a "4 bit wrap counter which
increments each time the TEST_CRC_x_x are updated."
However if we are trying to verify the screen hasn't changed we get
same (count, crc) pair twice. Without this patch we would return
-ETIMEOUT in this case.
So, if in 6 vblanks the pair (count, crc) hasn't changed we
return it anyway instead of returning error and let test case decide
if it was right or not.
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Rafael Antognolli <rafael.antognolli@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
| -rw-r--r-- | drivers/gpu/drm/i915/intel_dp.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index abcc2a36aa95..54e9b5380aa7 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -4065,6 +4065,7 @@ int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc) u8 buf; int count, ret; int attempts = 6; + bool old_equal_new; ret = intel_dp_sink_crc_start(intel_dp); if (ret) @@ -4079,6 +4080,7 @@ int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc) goto stop; } count = buf & DP_TEST_COUNT_MASK; + /* * Count might be reset during the loop. In this case * last known count needs to be reset as well. @@ -4090,17 +4092,24 @@ int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc) ret = -EIO; goto stop; } - } while (--attempts && (count == 0 || (count == intel_dp->sink_crc.last_count && - !memcmp(intel_dp->sink_crc.last_crc, crc, - 6 * sizeof(u8))))); + + old_equal_new = (count == intel_dp->sink_crc.last_count && + !memcmp(intel_dp->sink_crc.last_crc, crc, + 6 * sizeof(u8))); + + } while (--attempts && (count == 0 || old_equal_new)); intel_dp->sink_crc.last_count = buf & DP_TEST_COUNT_MASK; memcpy(intel_dp->sink_crc.last_crc, crc, 6 * sizeof(u8)); if (attempts == 0) { - DRM_DEBUG_KMS("Panel is unable to calculate CRC after 6 vblanks\n"); - ret = -ETIMEDOUT; - goto stop; + if (old_equal_new) { + DRM_DEBUG_KMS("Unreliable Sink CRC counter: Current returned CRC is identical to the previous one\n"); + } else { + DRM_ERROR("Panel is unable to calculate any CRC after 6 vblanks\n"); + ret = -ETIMEDOUT; + goto stop; + } } stop: |