drm/amd/display: Re-enable CRC capture following modeset

[Why]
During any modeset the CRTC stream is removed and a new stream is added.
This new stream doesn't carry over CRC capture state if it was
previously set.

[How]
Re-program the stream for CRC capture. The existing DRM callback can
be re-used here for the most part - the only modification needed is
additional locking now that it's called from within commit tail.
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Reviewed-by: Sun peng Li <Sunpeng.Li@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -4923,10 +4923,13 @@ static int amdgpu_dm_atomic_commit(struct drm_device *dev,
 		if (drm_atomic_crtc_needs_modeset(new_crtc_state)
 		    && dm_old_crtc_state->stream) {
 			/*
-			 * CRC capture was enabled but not disabled.
-			 * Release the vblank reference.
+			 * If the stream is removed and CRC capture was
+			 * enabled on the CRTC the extra vblank reference
+			 * needs to be dropped since CRC capture will be
+			 * disabled.
 			 */
-			if (dm_new_crtc_state->crc_enabled) {
+			if (!dm_new_crtc_state->stream
+			    && dm_new_crtc_state->crc_enabled) {
 				drm_crtc_vblank_put(crtc);
 				dm_new_crtc_state->crc_enabled = false;
 			}
@@ -5164,6 +5167,10 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
 			continue;
 
 		manage_dm_interrupts(adev, acrtc, true);
+
+		/* The stream has changed so CRC capture needs to re-enabled. */
+		if (dm_new_crtc_state->crc_enabled)
+			amdgpu_dm_crtc_set_crc_source(crtc, "auto");
 	}
 
 	/* update planes when needed per crtc*/

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crc.c

@@ -64,6 +64,7 @@ amdgpu_dm_crtc_verify_crc_source(struct drm_crtc *crtc, const char *src_name,
 
 int amdgpu_dm_crtc_set_crc_source(struct drm_crtc *crtc, const char *src_name)
 {
+	struct amdgpu_device *adev = crtc->dev->dev_private;
 	struct dm_crtc_state *crtc_state = to_dm_crtc_state(crtc->state);
 	struct dc_stream_state *stream_state = crtc_state->stream;
 	bool enable;
@@ -83,15 +84,20 @@ int amdgpu_dm_crtc_set_crc_source(struct drm_crtc *crtc, const char *src_name)
 
 	enable = (source == AMDGPU_DM_PIPE_CRC_SOURCE_AUTO);
 
+	mutex_lock(&adev->dm.dc_lock);
 	if (!dc_stream_configure_crc(stream_state->ctx->dc, stream_state,
-				     enable, enable))
+				     enable, enable)) {
+		mutex_unlock(&adev->dm.dc_lock);
 		return -EINVAL;
+	}
 
 	/* When enabling CRC, we should also disable dithering. */
 	dc_stream_set_dither_option(stream_state,
 				    enable ? DITHER_OPTION_TRUN8
 					   : DITHER_OPTION_DEFAULT);
 
+	mutex_unlock(&adev->dm.dc_lock);
+
 	/*
 	 * Reading the CRC requires the vblank interrupt handler to be
 	 * enabled. Keep a reference until CRC capture stops.