[PATCH 2/5] drm/i915: Grab uncore.lock around enabling vblank evasion

Maarten Lankhorst
2018-02-09T09:54:57Z

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
---
drivers/gpu/drm/i915/i915_irq.c | 2 +-
drivers/gpu/drm/i915/intel_drv.h | 1 +
drivers/gpu/drm/i915/intel_sprite.c | 10 ++++++----
3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index b886bd459acc..eda9543a0199 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -845,7 +845,7 @@ static u32 __intel_get_crtc_scanline_from_timestamp(struct intel_crtc *crtc)
}

/* I915_READ_FW, only for fast reads of display block, no need for forcewake etc. */
-static int __intel_get_crtc_scanline(struct intel_crtc *crtc)
+int __intel_get_crtc_scanline(struct intel_crtc *crtc)
{
struct drm_device *dev = crtc->base.dev;
struct drm_i915_private *dev_priv = to_i915(dev);
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 468ec1e90e16..fbdbbe741b2f 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1340,6 +1340,7 @@ static inline bool intel_irqs_enabled(struct drm_i915_private *dev_priv)
}

int intel_get_crtc_scanline(struct intel_crtc *crtc);
+int __intel_get_crtc_scanline(struct intel_crtc *crtc);
void gen8_irq_power_well_post_enable(struct drm_i915_private *dev_priv,
u8 pipe_mask);
void gen8_irq_power_well_pre_disable(struct drm_i915_private *dev_priv,
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 971a1ea0db45..3a34be4fd956 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -119,6 +119,7 @@ void intel_pipe_update_start(const struct intel_crtc_state *new_crtc_state)
crtc->debug.max_vbl = max;
trace_i915_pipe_update_start(crtc);

+ spin_lock(&dev_priv->uncore.lock);
for (;;) {
/*
* prepare_to_wait() has a memory barrier, which guarantees
@@ -127,7 +128,7 @@ void intel_pipe_update_start(const struct intel_crtc_state *new_crtc_state)
*/
prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE);

- scanline = intel_get_crtc_scanline(crtc);
+ scanline = __intel_get_crtc_scanline(crtc);
if (scanline < min || scanline > max)
break;

@@ -137,11 +138,11 @@ void intel_pipe_update_start(const struct intel_crtc_state *new_crtc_state)
break;
}

- local_irq_enable();
+ spin_unlock_irq(&dev_priv->uncore.lock);

timeout = schedule_timeout(timeout);

- local_irq_disable();
+ spin_lock_irq(&dev_priv->uncore.lock);
}

finish_wait(wq, &wait);
@@ -162,8 +163,9 @@ void intel_pipe_update_start(const struct intel_crtc_state *new_crtc_state)
* FIXME figure out if BXT+ DSI suffers from this as well
*/
while (need_vlv_dsi_wa && scanline == vblank_start)
- scanline = intel_get_crtc_scanline(crtc);
+ scanline = __intel_get_crtc_scanline(crtc);

+ spin_unlock(&dev_priv->uncore.lock);
crtc->debug.scanline_start = scanline;
crtc->debug.start_vbl_time = ktime_get();
crtc->debug.start_vbl_count = intel_crtc_get_vblank_counter(crtc);
--
2.16.1