drm/i915: Make Sink crc calculation waiting for counter to reset.
According to VESA DP spec TEST_CRC_COUNT (Bits 3:0) at
TEST_SINK_MISC (00246h) is "Reset to 0 when TEST_SINK bit 0 = 0;
So let's give few vblanks so we are really sure that this counter
is really zeroed on the next sink_crc read.
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 3ffedd8..a2d2636 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3953,6 +3953,8 @@
struct intel_crtc *intel_crtc = to_intel_crtc(dig_port->base.base.crtc);
u8 buf;
int ret = 0;
+ int count = 0;
+ int attempts = 10;
if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK, &buf) < 0) {
DRM_DEBUG_KMS("Sink CRC couldn't be stopped properly\n");
@@ -3967,7 +3969,22 @@
goto out;
}
- intel_wait_for_vblank(dev, intel_crtc->pipe);
+ do {
+ intel_wait_for_vblank(dev, intel_crtc->pipe);
+
+ if (drm_dp_dpcd_readb(&intel_dp->aux,
+ DP_TEST_SINK_MISC, &buf) < 0) {
+ ret = -EIO;
+ goto out;
+ }
+ count = buf & DP_TEST_COUNT_MASK;
+ } while (--attempts && count);
+
+ if (attempts == 0) {
+ DRM_ERROR("TIMEOUT: Sink CRC counter is not zeroed\n");
+ ret = -ETIMEDOUT;
+ }
+
intel_dp->sink_crc.started = false;
out:
hsw_enable_ips(intel_crtc);