drm/amd/display: Fix CRC vblank refs when changing interrupts

[Why]
We only currently drop the vblank reference when the stream is
being removed from the context. We should be dropping it whenever we
disable interrupts and reaquiring it after we re-enable them.

We also never get the extra reference correctly when re-enabling
interrupts, since grabbing the reference has the following condition:

if (!crtc_state->crc_enabled && enable)
        drm_crtc_vblank_get(crtc);

This means that crc_enabled must be *false* in order to grab the extra
reference.

[How]
Always drop the ref whenever we're disabling interrupts.

Only disable CRC capture when the stream is being removed.

Always grab the ref by setting dm_new_crtc_state->crc_enabled = false
before the call to re-enable CRC capture.

Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: David Francis <David.Francis@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 6bd7da6b25b5551608e0428050d9df18dcbb3a9c..4c19e187e4cb3415b0c3efd6ca9c48cc262d7f46 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -5476,16 +5476,18 @@ static int amdgpu_dm_atomic_commit(struct drm_device *dev,
                    (!dm_new_crtc_state->interrupts_enabled ||
                     drm_atomic_crtc_needs_modeset(new_crtc_state))) {
                        /*
-                        * 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 not
-                        * be re-enabled.
+                        * Drop the extra vblank reference added by CRC
+                        * capture if applicable.
                         */
-                       if (!dm_new_crtc_state->stream
-                           && dm_new_crtc_state->crc_enabled) {
+                       if (dm_new_crtc_state->crc_enabled)
                                drm_crtc_vblank_put(crtc);
+
+                       /*
+                        * Only keep CRC capture enabled if there's
+                        * still a stream for the CRTC.
+                        */
+                       if (!dm_new_crtc_state->stream)
                                dm_new_crtc_state->crc_enabled = false;
-                       }
 
                        manage_dm_interrupts(adev, acrtc, false);
                }
@@ -5737,8 +5739,10 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
 
 #ifdef CONFIG_DEBUG_FS
                /* The stream has changed so CRC capture needs to re-enabled. */
-               if (dm_new_crtc_state->crc_enabled)
+               if (dm_new_crtc_state->crc_enabled) {
+                       dm_new_crtc_state->crc_enabled = false;
                        amdgpu_dm_crtc_set_crc_source(crtc, "auto");
+               }
 #endif
        }