pipe_crc->lock only protects pipe_crc->skipped. Replace the lock with
atomic operations instead, it should work just as well, without the
spinlock. In the case we don't skip CRC in the irq, the fastpath is
only a single atomic_read().
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_drv.c | 1 -
drivers/gpu/drm/i915/i915_drv.h | 5 +----
drivers/gpu/drm/i915/i915_irq.c | 15 ++++++++-------
drivers/gpu/drm/i915/intel_pipe_crc.c | 20 +++-----------------
4 files changed, 12 insertions(+), 29 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index f770be18b2d7..8cb61e51eb33 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -938,7 +938,6 @@ static int i915_driver_init_early(struct drm_i915_private *dev_priv,
intel_init_display_hooks(dev_priv);
intel_init_clock_gating_hooks(dev_priv);
intel_init_audio_hooks(dev_priv);
- intel_display_crc_init(dev_priv);
intel_detect_preproduction_hw(dev_priv);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 4f139ab95547..648c41bb5bd1 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1264,8 +1264,7 @@ enum intel_pipe_crc_source {
#define INTEL_PIPE_CRC_ENTRIES_NR 128
struct intel_pipe_crc {
- spinlock_t lock;
- int skipped;
+ atomic_t skipped;
enum intel_pipe_crc_source source;
};
@@ -3323,12 +3322,10 @@ u32 i915_gem_fence_alignment(struct drm_i915_private *dev_priv, u32 size,
#ifdef CONFIG_DEBUG_FS
int i915_debugfs_register(struct drm_i915_private *dev_priv);
int i915_debugfs_connector_add(struct drm_connector *connector);
-void intel_display_crc_init(struct drm_i915_private *dev_priv);
#else
static inline int i915_debugfs_register(struct drm_i915_private *dev_priv) {return 0;}
static inline int i915_debugfs_connector_add(struct drm_connector *connector)
{ return 0; }
-static inline void intel_display_crc_init(struct drm_i915_private *dev_priv) {}
#endif
const char *i915_cache_level_str(struct drm_i915_private *i915, int type);
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index d8751881b0d2..20174b98aad9 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1682,8 +1682,8 @@ static void display_pipe_crc_irq_handler(struct drm_i915_private *dev_priv,
struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[pipe];
struct intel_crtc *crtc = intel_get_crtc_for_pipe(dev_priv, pipe);
uint32_t crcs[5];
+ int to_skip;
- spin_lock(&pipe_crc->lock);
/*
* For some not yet identified reason, the first CRC is
* bonkers. So let's just wait for the next vblank and read
@@ -1692,13 +1692,14 @@ static void display_pipe_crc_irq_handler(struct drm_i915_private *dev_priv,
* On GEN8+ sometimes the second CRC is bonkers as well, so
* don't trust that one either.
*/
- if (pipe_crc->skipped <= 0 ||
- (INTEL_GEN(dev_priv) >= 8 && pipe_crc->skipped == 1)) {
- pipe_crc->skipped++;
- spin_unlock(&pipe_crc->lock);
+
+ if (INTEL_GEN(dev_priv) >= 8)
+ to_skip = 2;
+ else
+ to_skip = 1;
+
+ if (atomic_add_unless(&pipe_crc->skipped, 1, to_skip))
return;
- }
- spin_unlock(&pipe_crc->lock);
crcs[0] = crc0;
crcs[1] = crc1;
diff --git a/drivers/gpu/drm/i915/intel_pipe_crc.c b/drivers/gpu/drm/i915/intel_pipe_crc.c
index 0e38c382e231..5320c1fcb3dc 100644
--- a/drivers/gpu/drm/i915/intel_pipe_crc.c
+++ b/drivers/gpu/drm/i915/intel_pipe_crc.c
@@ -458,17 +458,6 @@ display_crc_ctl_parse_source(const char *buf, enum intel_pipe_crc_source *s)
return -EINVAL;
}
-void intel_display_crc_init(struct drm_i915_private *dev_priv)
-{
- enum pipe pipe;
-
- for_each_pipe(dev_priv, pipe) {
- struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[pipe];
-
- spin_lock_init(&pipe_crc->lock);
- }
-}
-
int intel_crtc_set_crc_source(struct drm_crtc *crtc, const char *source_name,
size_t *values_cnt)
{
@@ -508,7 +497,7 @@ int intel_crtc_set_crc_source(struct drm_crtc *crtc, const char *source_name,
hsw_pipe_A_crc_wa(dev_priv, false);
}
- pipe_crc->skipped = 0;
+ atomic_set(&pipe_crc->skipped, 0);
*values_cnt = 5;
out:
@@ -530,8 +519,7 @@ void intel_crtc_enable_pipe_crc(struct intel_crtc *intel_crtc)
if (get_new_crc_ctl_reg(dev_priv, crtc->index, &pipe_crc->source, &val, false) < 0)
return;
- /* Don't need pipe_crc->lock here, IRQs are not generated. */
- pipe_crc->skipped = 0;
+ atomic_set(&pipe_crc->skipped, 0);
I915_WRITE(PIPE_CRC_CTL(crtc->index), val);
POSTING_READ(PIPE_CRC_CTL(crtc->index));
@@ -544,9 +532,7 @@ void intel_crtc_disable_pipe_crc(struct intel_crtc *intel_crtc)
struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[crtc->index];
/* Swallow crc's until we stop generating them. */
- spin_lock_irq(&pipe_crc->lock);
- pipe_crc->skipped = INT_MIN;
- spin_unlock_irq(&pipe_crc->lock);
+ atomic_set(&pipe_crc->skipped, INT_MIN);
I915_WRITE(PIPE_CRC_CTL(crtc->index), 0);
POSTING_READ(PIPE_CRC_CTL(crtc->index));
--
2.16.3
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