This patch adds a missing drm_crtc_vblank_put op to the pair drm_crtc_vblank_get/put (inc/decrement counter to guarantee vblanks). It clears the execution of the following kms_cursor_crc subtests: 1. pipe-A-cursor-[size,alpha-opaque, NxN-(on-screen, off-screen, sliding, random, fast-moving])] - successful when running individually. 2. pipe-A-cursor-dpms passes again 3. pipe-A-cursor-suspend also passes The issue was initially tracked in the sequential execution of IGT kms_cursor_crc subtest: when running the test sequence or one of its subtests twice, the odd execs complete and the pairs get stuck in an endless wait. In the IGT code, calling a wait_for_vblank before the start of CRC capture prevented the busy-wait. But the problem persisted in the pipe-A-cursor-dpms and -suspend subtests. Checking the history, the pipe-A-cursor-dpms subtest was successful when, in vkms_atomic_commit_tail, instead of using the flip_done op, it used wait_for_vblanks. Another way to prevent blocking was wait_one_vblank when enabling crtc. However, in both cases, pipe-A-cursor-suspend persisted blocking in the 2nd start of CRC capture, which may indicate that something got stuck in the step of CRC setup. Indeed, wait_one_vblank in the crc setup was able to sync things and free all kms_cursor_crc subtests. Tracing and comparing a clean run with a blocked one: - in a clean one, vkms_crtc_atomic_flush enables vblanks; - when blocked, only in next op, vkms_crtc_atomic_enable, the vblanks started. Moreover, a series of vkms_vblank_simulate flow out until disabling vblanks. Also watching the steps of vkms_crtc_atomic_flush, when the very first drm_crtc_vblank_get returned an error, the subtest crashed. On the other hand, when vblank_get succeeded, the subtest completed. Finally, checking the flush steps: it increases counter to hold a vblank reference (get), but there isn't a op to decreased it and release vblanks (put). Cc: Daniel Vetter <daniel@xxxxxxxx> Cc: Rodrigo Siqueira <rodrigosiqueiramelo@xxxxxxxxx> Cc: Haneen Mohammed <hamohammed.sa@xxxxxxxxx> Signed-off-by: Melissa Wen <melissa.srw@xxxxxxxxx> --- drivers/gpu/drm/vkms/vkms_crtc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms_crtc.c index ac85e17428f8..a99d6b4a92dd 100644 --- a/drivers/gpu/drm/vkms/vkms_crtc.c +++ b/drivers/gpu/drm/vkms/vkms_crtc.c @@ -246,6 +246,7 @@ static void vkms_crtc_atomic_flush(struct drm_crtc *crtc, spin_unlock(&crtc->dev->event_lock); + drm_crtc_vblank_put(crtc); crtc->state->event = NULL; } -- 2.27.0 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
