From 1ed134e6526b1b513a14fba938f6d96aa1c7f3dd Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Thu, 22 Jun 2017 22:25:26 +0200 Subject: 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 Reviewed-by: Eric Anholt Link: http://patchwork.freedesktop.org/patch/msgid/1498163126-26678-1-git-send-email-boris.brezillon@free-electrons.com Fixes: 34c8ea400ff6 ("drm/vc4: Mimic drm_atomic_helper_commit() behavior") --- 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 403bbd5f99a9..a12cc7ea99b6 100644 --- a/drivers/gpu/drm/vc4/vc4_crtc.c +++ b/drivers/gpu/drm/vc4/vc4_crtc.c @@ -520,6 +520,34 @@ 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; @@ -530,6 +558,12 @@ 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. */ @@ -541,9 +575,6 @@ 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, @@ -598,7 +629,6 @@ 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; @@ -620,25 +650,15 @@ 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)); -- cgit v1.2.3-59-g8ed1b