diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 2493ad2f5c12d198159d304719f23c1669713538..fff165a35ce718ceee68e681572f19ed92d4162c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -919,9 +919,11 @@ struct i915_fbc {
bool active;
struct intel_fbc_work {
- struct delayed_work work;
+ bool scheduled;
+ struct work_struct work;
struct drm_framebuffer *fb;
- } *fbc_work;
+ unsigned long enable_jiffies;
+ } work;
const char *no_fbc_reason;
diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
index 8460e3d72b98c4482567897886ad04aa06a8d198..07d3342b59de9d44124831d118395927955a2b19 100644
--- a/drivers/gpu/drm/i915/intel_fbc.c
+++ b/drivers/gpu/drm/i915/intel_fbc.c
@@ -392,85 +392,72 @@ static void intel_fbc_activate(const struct drm_framebuffer *fb)
static void intel_fbc_work_fn(struct work_struct *__work)
{
- struct intel_fbc_work *work =
- container_of(to_delayed_work(__work),
- struct intel_fbc_work, work);
- struct drm_i915_private *dev_priv = work->fb->dev->dev_private;
- struct drm_framebuffer *crtc_fb = dev_priv->fbc.crtc->base.primary->fb;
+ struct drm_i915_private *dev_priv =
+ container_of(__work, struct drm_i915_private, fbc.work.work);
+ struct intel_fbc_work *work = &dev_priv->fbc.work;
+ struct intel_crtc *crtc = dev_priv->fbc.crtc;
+ int delay_ms = 50;
+
+retry:
+ /* Delay the actual enabling to let pageflipping cease and the
+ * display to settle before starting the compression. Note that
+ * this delay also serves a second purpose: it allows for a
+ * vblank to pass after disabling the FBC before we attempt
+ * to modify the control registers.
+ *
+ * A more complicated solution would involve tracking vblanks
+ * following the termination of the page-flipping sequence
+ * and indeed performing the enable as a co-routine and not
+ * waiting synchronously upon the vblank.
+ *
+ * WaFbcWaitForVBlankBeforeEnable:ilk,snb
+ */
+ wait_remaining_ms_from_jiffies(work->enable_jiffies, delay_ms);
mutex_lock(&dev_priv->fbc.lock);
- if (work == dev_priv->fbc.fbc_work) {
- /* Double check that we haven't switched fb without cancelling
- * the prior work.
- */
- if (crtc_fb == work->fb)
- intel_fbc_activate(work->fb);
- dev_priv->fbc.fbc_work = NULL;
+ /* Were we cancelled? */
+ if (!work->scheduled)
+ goto out;
+
+ /* Were we delayed again while this function was sleeping? */
+ if (time_after(work->enable_jiffies + msecs_to_jiffies(delay_ms),
+ jiffies)) {
+ mutex_unlock(&dev_priv->fbc.lock);
+ goto retry;
}
- mutex_unlock(&dev_priv->fbc.lock);
- kfree(work);
+ if (crtc->base.primary->fb == work->fb)
+ intel_fbc_activate(work->fb);
+
+ work->scheduled = false;
+
+out:
+ mutex_unlock(&dev_priv->fbc.lock);
}
static void intel_fbc_cancel_work(struct drm_i915_private *dev_priv)
{
WARN_ON(!mutex_is_locked(&dev_priv->fbc.lock));
-
- if (dev_priv->fbc.fbc_work == NULL)
- return;
-
- /* Synchronisation is provided by struct_mutex and checking of
- * dev_priv->fbc.fbc_work, so we can perform the cancellation
- * entirely asynchronously.
- */
- if (cancel_delayed_work(&dev_priv->fbc.fbc_work->work))
- /* tasklet was killed before being run, clean up */
- kfree(dev_priv->fbc.fbc_work);
-
- /* Mark the work as no longer wanted so that if it does
- * wake-up (because the work was already running and waiting
- * for our mutex), it will discover that is no longer
- * necessary to run.
- */
- dev_priv->fbc.fbc_work = NULL;
+ dev_priv->fbc.work.scheduled = false;
}
static void intel_fbc_schedule_activation(struct intel_crtc *crtc)
{
- struct intel_fbc_work *work;
struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
+ struct intel_fbc_work *work = &dev_priv->fbc.work;
WARN_ON(!mutex_is_locked(&dev_priv->fbc.lock));
- intel_fbc_cancel_work(dev_priv);
-
- work = kzalloc(sizeof(*work), GFP_KERNEL);
- if (work == NULL) {
- DRM_ERROR("Failed to allocate FBC work structure\n");
- intel_fbc_activate(crtc->base.primary->fb);
- return;
- }
-
+ /* It is useless to call intel_fbc_cancel_work() in this function since
+ * we're not releasing fbc.lock, so it won't have an opportunity to grab
+ * it to discover that it was cancelled. So we just update the expected
+ * jiffy count. */
work->fb = crtc->base.primary->fb;
- INIT_DELAYED_WORK(&work->work, intel_fbc_work_fn);
+ work->scheduled = true;
+ work->enable_jiffies = jiffies;
- dev_priv->fbc.fbc_work = work;
-
- /* Delay the actual enabling to let pageflipping cease and the
- * display to settle before starting the compression. Note that
- * this delay also serves a second purpose: it allows for a
- * vblank to pass after disabling the FBC before we attempt
- * to modify the control registers.
- *
- * A more complicated solution would involve tracking vblanks
- * following the termination of the page-flipping sequence
- * and indeed performing the enable as a co-routine and not
- * waiting synchronously upon the vblank.
- *
- * WaFbcWaitForVBlankBeforeEnable:ilk,snb
- */
- schedule_delayed_work(&work->work, msecs_to_jiffies(50));
+ schedule_work(&work->work);
}
static void __intel_fbc_deactivate(struct drm_i915_private *dev_priv)
@@ -1106,9 +1093,11 @@ void intel_fbc_init(struct drm_i915_private *dev_priv)
{
enum pipe pipe;
+ INIT_WORK(&dev_priv->fbc.work.work, intel_fbc_work_fn);
mutex_init(&dev_priv->fbc.lock);
dev_priv->fbc.enabled = false;
dev_priv->fbc.active = false;
+ dev_priv->fbc.work.scheduled = false;
if (!HAS_FBC(dev_priv)) {
dev_priv->fbc.no_fbc_reason = "unsupported by this chipset";