diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_dp.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_dp.c | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 6f42d9568049..3caac0f01265 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -3807,21 +3807,32 @@ int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc) struct drm_device *dev = intel_dig_port->base.base.dev; struct intel_crtc *intel_crtc = to_intel_crtc(intel_dig_port->base.base.crtc); - u8 buf[1]; + u8 buf; + int test_crc_count; + int attempts = 6; - if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK_MISC, buf) < 0) + if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK_MISC, &buf) < 0) return -EIO; - if (!(buf[0] & DP_TEST_CRC_SUPPORTED)) + if (!(buf & DP_TEST_CRC_SUPPORTED)) return -ENOTTY; if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_TEST_SINK, DP_TEST_SINK_START) < 0) return -EIO; - /* Wait 2 vblanks to be sure we will have the correct CRC value */ - intel_wait_for_vblank(dev, intel_crtc->pipe); - intel_wait_for_vblank(dev, intel_crtc->pipe); + drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK_MISC, &buf); + test_crc_count = buf & DP_TEST_COUNT_MASK; + + do { + drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK_MISC, &buf); + intel_wait_for_vblank(dev, intel_crtc->pipe); + } while (--attempts && (buf & DP_TEST_COUNT_MASK) == test_crc_count); + + if (attempts == 0) { + DRM_ERROR("Panel is unable to calculate CRC after 6 vblanks\n"); + return -EIO; + } if (drm_dp_dpcd_read(&intel_dp->aux, DP_TEST_CRC_R_CR, crc, 6) < 0) return -EIO; |