From d40a5938a10a3ba73bce6395729fefd8b8bb1c07 Mon Sep 17 00:00:00 2001 From: Peter Robinson Date: Thu, 29 Jun 2017 10:05:05 +0100 Subject: [PATCH] drm/vc4: Fix VBLANK handling in crtc->enable() path When we are enabling a CRTC, drm_crtc_vblank_get() is called before drm_crtc_vblank_on(), which is not supposed to happen (hence the WARN_ON() in the code). To solve the problem, we delay the 'update display list' operation after the CRTC is actually enabled. Signed-off-by: Boris Brezillon --- drivers/gpu/drm/vc4/vc4_crtc.c | 66 +++++++++++++++++++++++++++--------------- 1 file changed, 43 insertions(+), 23 deletions(-) diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c index d86c8cce3182..316bd6210d69 100644 --- a/drivers/gpu/drm/vc4/vc4_crtc.c +++ b/drivers/gpu/drm/vc4/vc4_crtc.c @@ -530,6 +530,34 @@ static void vc4_crtc_disable(struct drm_crtc *crtc) SCALER_DISPSTATX_EMPTY); } +static void vc4_crtc_update_dlist(struct drm_crtc *crtc) +{ + struct drm_device *dev = crtc->dev; + struct vc4_dev *vc4 = to_vc4_dev(dev); + struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc); + struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state); + + 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; + + HVS_WRITE(SCALER_DISPLISTX(vc4_crtc->channel), + vc4_state->mm.start); + + spin_unlock_irqrestore(&dev->event_lock, flags); + } else { + HVS_WRITE(SCALER_DISPLISTX(vc4_crtc->channel), + vc4_state->mm.start); + } +} + static void vc4_crtc_enable(struct drm_crtc *crtc) { struct drm_device *dev = crtc->dev; @@ -540,6 +568,12 @@ static void vc4_crtc_enable(struct drm_crtc *crtc) require_hvs_enabled(dev); + /* Enable vblank irq handling before crtc is started otherwise + * drm_crtc_get_vblank() fails in vc4_crtc_update_dlist(). + */ + drm_crtc_vblank_on(crtc); + vc4_crtc_update_dlist(crtc); + /* Turn on the scaler, which will wait for vstart to start * compositing. */ @@ -551,9 +585,6 @@ static void vc4_crtc_enable(struct drm_crtc *crtc) /* Turn on the pixel valve, which will emit the vstart signal. */ CRTC_WRITE(PV_V_CONTROL, CRTC_READ(PV_V_CONTROL) | PV_VCONTROL_VIDEN); - - /* Enable vblank irq handling after crtc is started. */ - drm_crtc_vblank_on(crtc); } static bool vc4_crtc_mode_fixup(struct drm_crtc *crtc, @@ -608,7 +639,6 @@ static void vc4_crtc_atomic_flush(struct drm_crtc *crtc, { struct drm_device *dev = crtc->dev; struct vc4_dev *vc4 = to_vc4_dev(dev); - struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc); struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state); struct drm_plane *plane; bool debug_dump_regs = false; @@ -630,25 +660,15 @@ static void vc4_crtc_atomic_flush(struct drm_crtc *crtc, WARN_ON_ONCE(dlist_next - dlist_start != vc4_state->mm.size); - 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; - - HVS_WRITE(SCALER_DISPLISTX(vc4_crtc->channel), - vc4_state->mm.start); - - spin_unlock_irqrestore(&dev->event_lock, flags); - } else { - HVS_WRITE(SCALER_DISPLISTX(vc4_crtc->channel), - vc4_state->mm.start); - } + /* Only update DISPLIST if the CRTC was already running and is not + * being disabled. + * vc4_crtc_enable() takes care of updating the dlist just after + * re-enabling VBLANK interrupts and before enabling the engine. + * If the CRTC is being disabled, there's no point in updating this + * information. + */ + if (crtc->state->active && old_state->active) + vc4_crtc_update_dlist(crtc); if (debug_dump_regs) { DRM_INFO("CRTC %d HVS after:\n", drm_crtc_index(crtc)); -- 2.13.0