In some cases like when PSR just got enabled the panel need more vblank times to calculate CRC. I figured that out with the new PSR test cases facing some cases that I had a green screen but a blank CRC. Even with 2 vblank waits on kernel + 2 vblank waits on test case.
So let's give up to 6 vblank wait time. However we now check for TEST_CRC_COUNT that shows when panel finished to calculate CRC and has it ready.
v2: Jani pointed out attempts decrements was wrong and should never reach the error condition. And Daniel pointed out that EIO is more appropriated than EGAIN. Also I realized that I have to read test_crc_count after setting test_sink
Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Jani Nikula jani.nikula@intel.com Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com --- drivers/gpu/drm/i915/intel_dp.c | 21 +++++++++++++++------ include/drm/drm_dp_helper.h | 5 +++-- 2 files changed, 18 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index f79473b..fae0fae 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -3468,21 +3468,30 @@ 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 -EAGAIN;
- 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 -EAGAIN;
- /* 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) + return -EIO;
if (drm_dp_dpcd_read(&intel_dp->aux, DP_TEST_CRC_R_CR, crc, 6) < 0) return -EAGAIN; diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index 9305c71..8edeed0 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -303,7 +303,8 @@ #define DP_TEST_CRC_B_CB 0x244
#define DP_TEST_SINK_MISC 0x246 -#define DP_TEST_CRC_SUPPORTED (1 << 5) +# define DP_TEST_CRC_SUPPORTED (1 << 5) +# define DP_TEST_COUNT_MASK 0x7
#define DP_TEST_RESPONSE 0x260 # define DP_TEST_ACK (1 << 0) @@ -313,7 +314,7 @@ #define DP_TEST_EDID_CHECKSUM 0x261
#define DP_TEST_SINK 0x270 -#define DP_TEST_SINK_START (1 << 0) +# define DP_TEST_SINK_START (1 << 0)
#define DP_PAYLOAD_TABLE_UPDATE_STATUS 0x2c0 /* 1.2 MST */ # define DP_PAYLOAD_TABLE_UPDATED (1 << 0)