From 2b3a8cd71c2b830164df5de07e4ddebe0faa58f5 Mon Sep 17 00:00:00 2001 From: Tomi Valkeinen Date: Tue, 3 Nov 2015 12:00:51 +0200 Subject: [PATCH] drm/tilcdc: Do not update the next frame buffer close to vertical blank Do not update the next frame buffer close to vertical blank. This is to avoid situation when the frame changes between writing of LCDC_DMA_FB_BASE_ADDR_0_REG and LCDC_DMA_FB_CEILING_ADDR_0_REG. Signed-off-by: Tomi Valkeinen [Added description to the patch] Signed-off-by: Jyri Sarha --- drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 61 ++++++++++++++++++++++++---- 1 file changed, 53 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c index 3257228564d9..b1df04625f50 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c @@ -21,6 +21,8 @@ #include "tilcdc_drv.h" #include "tilcdc_regs.h" +#define TILCDC_VBLANK_SAFETY_THRESHOLD_US 1000 + struct tilcdc_crtc { struct drm_crtc base; @@ -29,8 +31,12 @@ struct tilcdc_crtc { int dpms; wait_queue_head_t frame_done_wq; bool frame_done; + spinlock_t irq_lock; + + ktime_t last_vblank; struct drm_framebuffer *curr_fb; + struct drm_framebuffer *next_fb; /* for deferred fb unref's: */ struct drm_flip_work unref_work; @@ -146,6 +152,8 @@ static int tilcdc_crtc_page_flip(struct drm_crtc *crtc, struct drm_device *dev = crtc->dev; int r; unsigned long flags; + s64 tdiff; + ktime_t next_vblank; r = tilcdc_verify_fb(crtc, fb); if (r) @@ -162,12 +170,21 @@ static int tilcdc_crtc_page_flip(struct drm_crtc *crtc, pm_runtime_get_sync(dev->dev); + spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags); + + next_vblank = ktime_add_us(tilcdc_crtc->last_vblank, + 1000000 / crtc->hwmode.vrefresh); - set_scanout(crtc, fb); + tdiff = ktime_to_us(ktime_sub(next_vblank, ktime_get())); + + if (tdiff >= TILCDC_VBLANK_SAFETY_THRESHOLD_US) + set_scanout(crtc, fb); + else + tilcdc_crtc->next_fb = fb; - spin_lock_irqsave(&dev->event_lock, flags); tilcdc_crtc->event = event; - spin_unlock_irqrestore(&dev->event_lock, flags); + + spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags); pm_runtime_put_sync(dev->dev); @@ -211,6 +228,12 @@ void tilcdc_crtc_dpms(struct drm_crtc *crtc, int mode) pm_runtime_put_sync(dev->dev); + if (tilcdc_crtc->next_fb) { + drm_flip_work_queue(&tilcdc_crtc->unref_work, + tilcdc_crtc->next_fb); + tilcdc_crtc->next_fb = NULL; + } + if (tilcdc_crtc->curr_fb) { drm_flip_work_queue(&tilcdc_crtc->unref_work, tilcdc_crtc->curr_fb); @@ -651,19 +674,39 @@ irqreturn_t tilcdc_crtc_irq(struct drm_crtc *crtc) if (stat & LCDC_END_OF_FRAME0) { unsigned long flags; + bool skip_event = false; + ktime_t now; + + now = ktime_get(); drm_flip_work_commit(&tilcdc_crtc->unref_work, priv->wq); + spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags); + + tilcdc_crtc->last_vblank = now; + + if (tilcdc_crtc->next_fb) { + set_scanout(crtc, tilcdc_crtc->next_fb); + tilcdc_crtc->next_fb = NULL; + skip_event = true; + } + + spin_unlock_irqrestore(&tilcdc_crtc->irq_lock, flags); + drm_handle_vblank(dev, 0); - spin_lock_irqsave(&dev->event_lock, flags); + if (!skip_event) { + struct drm_pending_vblank_event *event; - if (tilcdc_crtc->event) { - drm_send_vblank_event(dev, 0, tilcdc_crtc->event); + spin_lock_irqsave(&dev->event_lock, flags); + + event = tilcdc_crtc->event; tilcdc_crtc->event = NULL; - } + if (event) + drm_send_vblank_event(dev, 0, event); - spin_unlock_irqrestore(&dev->event_lock, flags); + spin_unlock_irqrestore(&dev->event_lock, flags); + } } if (priv->rev == 2) { @@ -697,6 +740,8 @@ struct drm_crtc *tilcdc_crtc_create(struct drm_device *dev) drm_flip_work_init(&tilcdc_crtc->unref_work, "unref", unref_worker); + spin_lock_init(&tilcdc_crtc->irq_lock); + ret = drm_crtc_init(dev, crtc, &tilcdc_crtc_funcs); if (ret < 0) goto fail; -- 2.34.1