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path: root/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
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Diffstat (limited to 'drivers/gpu/drm/tilcdc/tilcdc_crtc.c')
-rw-r--r--drivers/gpu/drm/tilcdc/tilcdc_crtc.c37
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 f80bf9385e41..d745e8b50fb8 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;
}
@@ -1036,5 +1047,5 @@ int tilcdc_crtc_create(struct drm_device *dev)
fail:
tilcdc_crtc_destroy(crtc);
- return -ENOMEM;
+ return ret;
}