diff options
Diffstat (limited to 'drivers/gpu/drm/tilcdc/tilcdc_crtc.c')
-rw-r--r-- | drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 37 |
1 files changed, 24 insertions, 13 deletions
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c index 93505bc..c92faa8 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c @@ -464,6 +464,7 @@ static void tilcdc_crtc_enable(struct drm_crtc *crtc) { struct drm_device *dev = crtc->dev; struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc); + unsigned long flags; WARN_ON(!drm_modeset_is_locked(&crtc->mutex)); mutex_lock(&tilcdc_crtc->enable_lock); @@ -484,7 +485,17 @@ static void tilcdc_crtc_enable(struct drm_crtc *crtc) tilcdc_write_mask(dev, LCDC_RASTER_CTRL_REG, LCDC_PALETTE_LOAD_MODE(DATA_ONLY), LCDC_PALETTE_LOAD_MODE_MASK); + + /* There is no real chance for a race here as the time stamp + * is taken before the raster DMA is started. The spin-lock is + * taken to have a memory barrier after taking the time-stamp + * and to avoid a context switch between taking the stamp and + * enabling the raster. + */ + spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags); + tilcdc_crtc->last_vblank = ktime_get(); tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE); + spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags); drm_crtc_vblank_on(crtc); @@ -539,7 +550,6 @@ static void tilcdc_crtc_off(struct drm_crtc *crtc, bool shutdown) } drm_flip_work_commit(&tilcdc_crtc->unref_work, priv->wq); - tilcdc_crtc->last_vblank = 0; tilcdc_crtc->enabled = false; mutex_unlock(&tilcdc_crtc->enable_lock); @@ -602,7 +612,6 @@ int tilcdc_crtc_update_fb(struct drm_crtc *crtc, { struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc); struct drm_device *dev = crtc->dev; - unsigned long flags; WARN_ON(!drm_modeset_is_locked(&crtc->mutex)); @@ -614,28 +623,30 @@ int tilcdc_crtc_update_fb(struct drm_crtc *crtc, drm_framebuffer_reference(fb); crtc->primary->fb = fb; + tilcdc_crtc->event = event; - spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags); + mutex_lock(&tilcdc_crtc->enable_lock); - if (crtc->hwmode.vrefresh && ktime_to_ns(tilcdc_crtc->last_vblank)) { + if (tilcdc_crtc->enabled) { + unsigned long flags; ktime_t next_vblank; s64 tdiff; - next_vblank = ktime_add_us(tilcdc_crtc->last_vblank, - 1000000 / crtc->hwmode.vrefresh); + spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags); + next_vblank = ktime_add_us(tilcdc_crtc->last_vblank, + 1000000 / crtc->hwmode.vrefresh); tdiff = ktime_to_us(ktime_sub(next_vblank, ktime_get())); if (tdiff < TILCDC_VBLANK_SAFETY_THRESHOLD_US) tilcdc_crtc->next_fb = fb; - } - - if (tilcdc_crtc->next_fb != fb) - set_scanout(crtc, fb); + else + set_scanout(crtc, fb); - tilcdc_crtc->event = event; + spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags); + } - spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags); + mutex_unlock(&tilcdc_crtc->enable_lock); return 0; } @@ -1047,5 +1058,5 @@ int tilcdc_crtc_create(struct drm_device *dev) fail: tilcdc_crtc_destroy(crtc); - return -ENOMEM; + return ret; } |