* [PATCH] drm/i915: Use a global lock for modifying global irq flags
@ 2012-04-24 20:48 Chris Wilson
2012-04-24 21:05 ` Ben Widawsky
0 siblings, 1 reply; 3+ messages in thread
From: Chris Wilson @ 2012-04-24 20:48 UTC (permalink / raw)
To: intel-gfx
We were attempting to use a per-ring spinlock whilst modifying global
IRQ flags. A recipe for rare missed interrupts.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/intel_ringbuffer.c | 41 ++++++++++++++++++-------------
drivers/gpu/drm/i915/intel_ringbuffer.h | 3 +--
2 files changed, 25 insertions(+), 19 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index f797613..b7f446e 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -610,17 +610,18 @@ gen5_ring_get_irq(struct intel_ring_buffer *ring)
{
struct drm_device *dev = ring->dev;
drm_i915_private_t *dev_priv = dev->dev_private;
+ unsigned long flags;
if (!dev->irq_enabled)
return false;
- spin_lock(&ring->irq_lock);
+ spin_lock_irqsave(&dev_priv->irq_lock, flags);
if (ring->irq_refcount++ == 0) {
dev_priv->gt_irq_mask &= ~ring->irq_enable_mask;
I915_WRITE(GTIMR, dev_priv->gt_irq_mask);
POSTING_READ(GTIMR);
}
- spin_unlock(&ring->irq_lock);
+ spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
return true;
}
@@ -630,14 +631,15 @@ gen5_ring_put_irq(struct intel_ring_buffer *ring)
{
struct drm_device *dev = ring->dev;
drm_i915_private_t *dev_priv = dev->dev_private;
+ unsigned long flags;
- spin_lock(&ring->irq_lock);
+ spin_lock_irqsave(&dev_priv->irq_lock, flags);
if (--ring->irq_refcount == 0) {
dev_priv->gt_irq_mask |= ring->irq_enable_mask;
I915_WRITE(GTIMR, dev_priv->gt_irq_mask);
POSTING_READ(GTIMR);
}
- spin_unlock(&ring->irq_lock);
+ spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
}
static bool
@@ -645,17 +647,18 @@ i9xx_ring_get_irq(struct intel_ring_buffer *ring)
{
struct drm_device *dev = ring->dev;
drm_i915_private_t *dev_priv = dev->dev_private;
+ unsigned long flags;
if (!dev->irq_enabled)
return false;
- spin_lock(&ring->irq_lock);
+ spin_lock_irqsave(&dev_priv->irq_lock, flags);
if (ring->irq_refcount++ == 0) {
dev_priv->irq_mask &= ~ring->irq_enable_mask;
I915_WRITE(IMR, dev_priv->irq_mask);
POSTING_READ(IMR);
}
- spin_unlock(&ring->irq_lock);
+ spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
return true;
}
@@ -665,14 +668,15 @@ i9xx_ring_put_irq(struct intel_ring_buffer *ring)
{
struct drm_device *dev = ring->dev;
drm_i915_private_t *dev_priv = dev->dev_private;
+ unsigned long flags;
- spin_lock(&ring->irq_lock);
+ spin_lock_irqsave(&dev_priv->irq_lock, flags);
if (--ring->irq_refcount == 0) {
dev_priv->irq_mask |= ring->irq_enable_mask;
I915_WRITE(IMR, dev_priv->irq_mask);
POSTING_READ(IMR);
}
- spin_unlock(&ring->irq_lock);
+ spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
}
static bool
@@ -680,17 +684,18 @@ i8xx_ring_get_irq(struct intel_ring_buffer *ring)
{
struct drm_device *dev = ring->dev;
drm_i915_private_t *dev_priv = dev->dev_private;
+ unsigned long flags;
if (!dev->irq_enabled)
return false;
- spin_lock(&ring->irq_lock);
+ spin_lock_irqsave(&dev_priv->irq_lock, flags);
if (ring->irq_refcount++ == 0) {
dev_priv->irq_mask &= ~ring->irq_enable_mask;
I915_WRITE16(IMR, dev_priv->irq_mask);
POSTING_READ16(IMR);
}
- spin_unlock(&ring->irq_lock);
+ spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
return true;
}
@@ -700,14 +705,15 @@ i8xx_ring_put_irq(struct intel_ring_buffer *ring)
{
struct drm_device *dev = ring->dev;
drm_i915_private_t *dev_priv = dev->dev_private;
+ unsigned long flags;
- spin_lock(&ring->irq_lock);
+ spin_lock_irqsave(&dev_priv->irq_lock, flags);
if (--ring->irq_refcount == 0) {
dev_priv->irq_mask |= ring->irq_enable_mask;
I915_WRITE16(IMR, dev_priv->irq_mask);
POSTING_READ16(IMR);
}
- spin_unlock(&ring->irq_lock);
+ spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
}
void intel_ring_setup_status_page(struct intel_ring_buffer *ring)
@@ -786,6 +792,7 @@ gen6_ring_get_irq(struct intel_ring_buffer *ring)
{
struct drm_device *dev = ring->dev;
drm_i915_private_t *dev_priv = dev->dev_private;
+ unsigned long flags;
if (!dev->irq_enabled)
return false;
@@ -795,14 +802,14 @@ gen6_ring_get_irq(struct intel_ring_buffer *ring)
* blt/bsd rings on ivb. */
gen6_gt_force_wake_get(dev_priv);
- spin_lock(&ring->irq_lock);
+ spin_lock_irqsave(&dev_priv->irq_lock, flags);
if (ring->irq_refcount++ == 0) {
I915_WRITE_IMR(ring, ~ring->irq_enable_mask);
dev_priv->gt_irq_mask &= ~ring->irq_enable_mask;
I915_WRITE(GTIMR, dev_priv->gt_irq_mask);
POSTING_READ(GTIMR);
}
- spin_unlock(&ring->irq_lock);
+ spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
return true;
}
@@ -812,15 +819,16 @@ gen6_ring_put_irq(struct intel_ring_buffer *ring)
{
struct drm_device *dev = ring->dev;
drm_i915_private_t *dev_priv = dev->dev_private;
+ unsigned long flags;
- spin_lock(&ring->irq_lock);
+ spin_lock_irqsave(&dev_priv->irq_lock, flags);
if (--ring->irq_refcount == 0) {
I915_WRITE_IMR(ring, ~0);
dev_priv->gt_irq_mask |= ring->irq_enable_mask;
I915_WRITE(GTIMR, dev_priv->gt_irq_mask);
POSTING_READ(GTIMR);
}
- spin_unlock(&ring->irq_lock);
+ spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
gen6_gt_force_wake_put(dev_priv);
}
@@ -954,7 +962,6 @@ static int intel_init_ring_buffer(struct drm_device *dev,
ring->size = 32 * PAGE_SIZE;
init_waitqueue_head(&ring->irq_queue);
- spin_lock_init(&ring->irq_lock);
if (I915_NEED_GFX_HWS(dev)) {
ret = init_status_page(ring);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 06a66ad..e0b25bb 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -56,8 +56,7 @@ struct intel_ring_buffer {
*/
u32 last_retired_head;
- spinlock_t irq_lock;
- u32 irq_refcount;
+ u32 irq_refcount; /* protected by dev_priv->irq_lock */
u32 irq_enable_mask; /* bitmask to enable ring interrupt */
u32 irq_seqno; /* last seq seem at irq time */
u32 trace_irq_seqno;
--
1.7.10
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] drm/i915: Use a global lock for modifying global irq flags
2012-04-24 20:48 [PATCH] drm/i915: Use a global lock for modifying global irq flags Chris Wilson
@ 2012-04-24 21:05 ` Ben Widawsky
2012-04-25 8:21 ` Daniel Vetter
0 siblings, 1 reply; 3+ messages in thread
From: Ben Widawsky @ 2012-04-24 21:05 UTC (permalink / raw)
To: Chris Wilson; +Cc: intel-gfx
On Tue, 24 Apr 2012 21:48:47 +0100
Chris Wilson <chris@chris-wilson.co.uk> wrote:
> We were attempting to use a per-ring spinlock whilst modifying global
> IRQ flags. A recipe for rare missed interrupts.
>
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Regardless of whether or not this currently fixes anything, I need this
for an upcoming patch.
Acked-by: Ben Widawsky <ben@bwidawsk.net>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] drm/i915: Use a global lock for modifying global irq flags
2012-04-24 21:05 ` Ben Widawsky
@ 2012-04-25 8:21 ` Daniel Vetter
0 siblings, 0 replies; 3+ messages in thread
From: Daniel Vetter @ 2012-04-25 8:21 UTC (permalink / raw)
To: Ben Widawsky; +Cc: intel-gfx
On Tue, Apr 24, 2012 at 02:05:25PM -0700, Ben Widawsky wrote:
> On Tue, 24 Apr 2012 21:48:47 +0100
> Chris Wilson <chris@chris-wilson.co.uk> wrote:
>
> > We were attempting to use a per-ring spinlock whilst modifying global
> > IRQ flags. A recipe for rare missed interrupts.
> >
> > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
>
> Regardless of whether or not this currently fixes anything, I need this
> for an upcoming patch.
>
> Acked-by: Ben Widawsky <ben@bwidawsk.net>
Queued for -next, thanks for the patch.
-Daniel
--
Daniel Vetter
Mail: daniel@ffwll.ch
Mobile: +41 (0)79 365 57 48
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2012-04-25 8:20 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-04-24 20:48 [PATCH] drm/i915: Use a global lock for modifying global irq flags Chris Wilson
2012-04-24 21:05 ` Ben Widawsky
2012-04-25 8:21 ` Daniel Vetter
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox