From 348c4cda526660cc04c1f9ea3add9f0e64cb46ff Mon Sep 17 00:00:00 2001 From: Dave Stevenson Date: Thu, 25 Jul 2019 17:27:44 +0100 Subject: [PATCH] drm/vc4: Resolve the vblank warnings on mode switching The details over when and how a driver is to service the vblank events are sketchy, and the fkms driver was triggering a kernel warning every time the crtc was enabled or disabled. Copy the event handling as used by the vc4-kms driver slightly more closely, and we avoid the warnings. https://github.com/raspberrypi/linux/issues/3020 Signed-off-by: Dave Stevenson --- drivers/gpu/drm/vc4/vc4_firmware_kms.c | 48 ++++++++++++++++++-------- 1 file changed, 33 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/vc4/vc4_firmware_kms.c b/drivers/gpu/drm/vc4/vc4_firmware_kms.c index fa8a538f5d6698..d9779b993c3923 100644 --- a/drivers/gpu/drm/vc4/vc4_firmware_kms.c +++ b/drivers/gpu/drm/vc4/vc4_firmware_kms.c @@ -964,6 +964,7 @@ static void vc4_crtc_mode_set_nofb(struct drm_crtc *crtc) static void vc4_crtc_disable(struct drm_crtc *crtc, struct drm_crtc_state *old_state) { + struct drm_device *dev = crtc->dev; struct drm_plane *plane; DRM_DEBUG_KMS("[CRTC:%d] vblanks off.\n", @@ -979,6 +980,35 @@ static void vc4_crtc_disable(struct drm_crtc *crtc, struct drm_crtc_state *old_s drm_atomic_crtc_for_each_plane(plane, crtc) vc4_plane_atomic_disable(plane, plane->state); + + /* + * Make sure we issue a vblank event after disabling the CRTC if + * someone was waiting it. + */ + if (crtc->state->event) { + unsigned long flags; + + spin_lock_irqsave(&dev->event_lock, flags); + drm_crtc_send_vblank_event(crtc, crtc->state->event); + crtc->state->event = NULL; + spin_unlock_irqrestore(&dev->event_lock, flags); + } +} + +static void vc4_crtc_consume_event(struct drm_crtc *crtc) +{ + struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc); + struct drm_device *dev = crtc->dev; + unsigned long flags; + + crtc->state->event->pipe = drm_crtc_index(crtc); + + WARN_ON(drm_crtc_vblank_get(crtc) != 0); + + spin_lock_irqsave(&dev->event_lock, flags); + vc4_crtc->event = crtc->state->event; + crtc->state->event = NULL; + spin_unlock_irqrestore(&dev->event_lock, flags); } static void vc4_crtc_enable(struct drm_crtc *crtc, struct drm_crtc_state *old_state) @@ -988,6 +1018,7 @@ static void vc4_crtc_enable(struct drm_crtc *crtc, struct drm_crtc_state *old_st DRM_DEBUG_KMS("[CRTC:%d] vblanks on.\n", crtc->base.id); drm_crtc_vblank_on(crtc); + vc4_crtc_consume_event(crtc); /* Unblank the planes (if they're supposed to be displayed). */ drm_atomic_crtc_for_each_plane(plane, crtc) @@ -1059,23 +1090,10 @@ static int vc4_crtc_atomic_check(struct drm_crtc *crtc, static void vc4_crtc_atomic_flush(struct drm_crtc *crtc, struct drm_crtc_state *old_state) { - struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc); - struct drm_device *dev = crtc->dev; - DRM_DEBUG_KMS("[CRTC:%d] crtc_atomic_flush.\n", crtc->base.id); - if (crtc->state->event) { - unsigned long flags; - - crtc->state->event->pipe = drm_crtc_index(crtc); - - WARN_ON(drm_crtc_vblank_get(crtc) != 0); - - spin_lock_irqsave(&dev->event_lock, flags); - vc4_crtc->event = crtc->state->event; - crtc->state->event = NULL; - spin_unlock_irqrestore(&dev->event_lock, flags); - } + if (crtc->state->active && old_state->active && crtc->state->event) + vc4_crtc_consume_event(crtc); } static void vc4_crtc_handle_page_flip(struct vc4_crtc *vc4_crtc)