[PATCH 2/2] drm/i915: Remove delayed FBC activation.
Maarten Lankhorst
maarten.lankhorst at linux.intel.com
Mon Jun 25 11:54:27 UTC 2018
The only time we should start FBC is when we have waited a vblank
after the atomic update. We've already forced a vblank wait by doing
wait_for_flip_done before intel_post_plane_update(), so we don't need
to wait a second time before enabling.
Removing the worker simplifies the code and removes possible race
conditions, like happening in 103167.
Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103167
Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
---
drivers/gpu/drm/i915/i915_debugfs.c | 5 --
drivers/gpu/drm/i915/i915_drv.h | 6 --
drivers/gpu/drm/i915/intel_fbc.c | 96 +----------------------------
3 files changed, 1 insertion(+), 106 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index c400f42a54ec..48a57c0636bf 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1659,11 +1659,6 @@ static int i915_fbc_status(struct seq_file *m, void *unused)
else
seq_printf(m, "FBC disabled: %s\n", fbc->no_fbc_reason);
- if (fbc->work.scheduled)
- seq_printf(m, "FBC worker scheduled on vblank %llu, now %llu\n",
- fbc->work.scheduled_vblank,
- drm_crtc_vblank_count(&fbc->crtc->base));
-
if (intel_fbc_is_active(dev_priv)) {
u32 mask;
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 328d4312c438..9645dcb30454 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -580,12 +580,6 @@ struct intel_fbc {
unsigned int gen9_wa_cfb_stride;
} params;
- struct intel_fbc_work {
- bool scheduled;
- u64 scheduled_vblank;
- struct work_struct work;
- } 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 9f9ea0b5452f..01d1d2088f04 100644
--- a/drivers/gpu/drm/i915/intel_fbc.c
+++ b/drivers/gpu/drm/i915/intel_fbc.c
@@ -399,89 +399,6 @@ bool intel_fbc_is_active(struct drm_i915_private *dev_priv)
return dev_priv->fbc.active;
}
-static void intel_fbc_work_fn(struct work_struct *__work)
-{
- struct drm_i915_private *dev_priv =
- container_of(__work, struct drm_i915_private, fbc.work.work);
- struct intel_fbc *fbc = &dev_priv->fbc;
- struct intel_fbc_work *work = &fbc->work;
- struct intel_crtc *crtc = fbc->crtc;
- struct drm_vblank_crtc *vblank = &dev_priv->drm.vblank[crtc->pipe];
-
- if (drm_crtc_vblank_get(&crtc->base)) {
- /* CRTC is now off, leave FBC deactivated */
- mutex_lock(&fbc->lock);
- work->scheduled = false;
- mutex_unlock(&fbc->lock);
- return;
- }
-
-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.
- *
- * WaFbcWaitForVBlankBeforeEnable:ilk,snb
- *
- * It is also worth mentioning that since work->scheduled_vblank can be
- * updated multiple times by the other threads, hitting the timeout is
- * not an error condition. We'll just end up hitting the "goto retry"
- * case below.
- */
- wait_event_timeout(vblank->queue,
- drm_crtc_vblank_count(&crtc->base) != work->scheduled_vblank,
- msecs_to_jiffies(50));
-
- mutex_lock(&fbc->lock);
-
- /* Were we cancelled? */
- if (!work->scheduled)
- goto out;
-
- /* Were we delayed again while this function was sleeping? */
- if (drm_crtc_vblank_count(&crtc->base) == work->scheduled_vblank) {
- mutex_unlock(&fbc->lock);
- goto retry;
- }
-
- intel_fbc_hw_activate(dev_priv);
-
- work->scheduled = false;
-
-out:
- mutex_unlock(&fbc->lock);
- drm_crtc_vblank_put(&crtc->base);
-}
-
-static void intel_fbc_schedule_activation(struct intel_crtc *crtc)
-{
- struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
- struct intel_fbc *fbc = &dev_priv->fbc;
- struct intel_fbc_work *work = &fbc->work;
-
- WARN_ON(!mutex_is_locked(&fbc->lock));
- if (WARN_ON(!fbc->enabled))
- return;
-
- if (drm_crtc_vblank_get(&crtc->base)) {
- DRM_ERROR("vblank not available for FBC on pipe %c\n",
- pipe_name(crtc->pipe));
- return;
- }
-
- /* It is useless to call intel_fbc_cancel_work() or 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->scheduled = true;
- work->scheduled_vblank = drm_crtc_vblank_count(&crtc->base);
- drm_crtc_vblank_put(&crtc->base);
-
- schedule_work(&work->work);
-}
-
static void intel_fbc_deactivate(struct drm_i915_private *dev_priv,
const char *reason)
{
@@ -489,11 +406,6 @@ static void intel_fbc_deactivate(struct drm_i915_private *dev_priv,
WARN_ON(!mutex_is_locked(&fbc->lock));
- /* Calling cancel_work() here won't help due to the fact that the work
- * function grabs fbc->lock. Just set scheduled to false so the work
- * function can know it was cancelled. */
- fbc->work.scheduled = false;
-
if (fbc->active)
intel_fbc_hw_deactivate(dev_priv);
@@ -1005,7 +917,7 @@ static void __intel_fbc_post_update(struct intel_crtc *crtc)
if (!fbc->busy_bits) {
intel_fbc_deactivate(dev_priv, "FBC enabled (active or scheduled)");
- intel_fbc_schedule_activation(crtc);
+ intel_fbc_hw_activate(dev_priv);
} else
intel_fbc_deactivate(dev_priv, "frontbuffer write");
}
@@ -1212,8 +1124,6 @@ void intel_fbc_disable(struct intel_crtc *crtc)
if (fbc->crtc == crtc)
__intel_fbc_disable(dev_priv);
mutex_unlock(&fbc->lock);
-
- cancel_work_sync(&fbc->work.work);
}
/**
@@ -1235,8 +1145,6 @@ void intel_fbc_global_disable(struct drm_i915_private *dev_priv)
__intel_fbc_disable(dev_priv);
}
mutex_unlock(&fbc->lock);
-
- cancel_work_sync(&fbc->work.work);
}
static void intel_fbc_underrun_work_fn(struct work_struct *work)
@@ -1387,12 +1295,10 @@ void intel_fbc_init(struct drm_i915_private *dev_priv)
{
struct intel_fbc *fbc = &dev_priv->fbc;
- INIT_WORK(&fbc->work.work, intel_fbc_work_fn);
INIT_WORK(&fbc->underrun_work, intel_fbc_underrun_work_fn);
mutex_init(&fbc->lock);
fbc->enabled = false;
fbc->active = false;
- fbc->work.scheduled = false;
if (need_fbc_vtd_wa(dev_priv))
mkwrite_device_info(dev_priv)->has_fbc = false;
--
2.18.0
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