diff mbox

[v2] drm/i915: Flush idle work when changing missed-irq fault injection

Message ID 20170306101541.26171-1-chris@chris-wilson.co.uk (mailing list archive)
State New, archived
Headers show

Commit Message

Chris Wilson March 6, 2017, 10:15 a.m. UTC
In order for the missed-irq update to take effect, the device must be
idle. So when the user updates the fault injection via debugfs, idle the
device.

v2: Idle is explicitly required for setting test_irq, and good behaviour
for clearing the missed_irq.

Testcase: igt/drv_missed_irq
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 55 +++++++++++++++++++++++++------------
 1 file changed, 38 insertions(+), 17 deletions(-)

Comments

Tvrtko Ursulin March 6, 2017, 5:45 p.m. UTC | #1
On 06/03/2017 10:15, Chris Wilson wrote:
> In order for the missed-irq update to take effect, the device must be
> idle. So when the user updates the fault injection via debugfs, idle the
> device.
>
> v2: Idle is explicitly required for setting test_irq, and good behaviour
> for clearing the missed_irq.
>
> Testcase: igt/drv_missed_irq
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> ---
>  drivers/gpu/drm/i915/i915_debugfs.c | 55 +++++++++++++++++++++++++------------
>  1 file changed, 38 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 4a3e5b9552f8..511d3541d3d5 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -4138,6 +4138,39 @@ DEFINE_SIMPLE_ATTRIBUTE(i915_wedged_fops,
>  			"%llu\n");
>
>  static int
> +fault_irq_set(struct drm_i915_private *i915, unsigned long *irq, u64 val)
> +{
> +	int err;
> +
> +	err = mutex_lock_interruptible(&i915->drm.struct_mutex);
> +	if (err)
> +		return err;
> +
> +	err = i915_gem_wait_for_idle(i915,
> +				     I915_WAIT_LOCKED |
> +				     I915_WAIT_INTERRUPTIBLE);
> +	if (err)
> +		goto err_unlock;
> +
> +	/* Retire to kick idle work */
> +	i915_gem_retire_requests(i915);
> +	GEM_BUG_ON(i915->gt.active_requests);
> +
> +	*irq = val & INTEL_INFO(i915)->ring_mask;

Looks like a type width mismatch on 32-bit.

Should we change missed_irq_rings to an u64?

> +	mutex_unlock(&i915->drm.struct_mutex);
> +
> +	/* Flush idle worker to disarm irq */
> +	while (flush_delayed_work(&i915->gt.idle_work))
> +		;

Worth sticking a schedule in here or something? Not worth it for debugfs 
I guess since we don't have it elsewhere.

> +
> +	return 0;
> +
> +err_unlock:
> +	mutex_unlock(&i915->drm.struct_mutex);
> +	return err;
> +}
> +
> +static int
>  i915_ring_missed_irq_get(void *data, u64 *val)
>  {
>  	struct drm_i915_private *dev_priv = data;
> @@ -4149,18 +4182,8 @@ i915_ring_missed_irq_get(void *data, u64 *val)
>  static int
>  i915_ring_missed_irq_set(void *data, u64 val)
>  {
> -	struct drm_i915_private *dev_priv = data;
> -	struct drm_device *dev = &dev_priv->drm;
> -	int ret;
> -
> -	/* Lock against concurrent debugfs callers */
> -	ret = mutex_lock_interruptible(&dev->struct_mutex);
> -	if (ret)
> -		return ret;
> -	dev_priv->gpu_error.missed_irq_rings = val;
> -	mutex_unlock(&dev->struct_mutex);
> -
> -	return 0;
> +	struct drm_i915_private *i915 = data;
> +	return fault_irq_set(i915, &i915->gpu_error.missed_irq_rings, val);
>  }
>
>  DEFINE_SIMPLE_ATTRIBUTE(i915_ring_missed_irq_fops,
> @@ -4180,13 +4203,11 @@ i915_ring_test_irq_get(void *data, u64 *val)
>  static int
>  i915_ring_test_irq_set(void *data, u64 val)
>  {
> -	struct drm_i915_private *dev_priv = data;
> +	struct drm_i915_private *i915 = data;
>
> -	val &= INTEL_INFO(dev_priv)->ring_mask;
> +	val &= INTEL_INFO(i915)->ring_mask;
>  	DRM_DEBUG_DRIVER("Masking interrupts on rings 0x%08llx\n", val);
> -	dev_priv->gpu_error.test_irq_rings = val;
> -
> -	return 0;
> +	return fault_irq_set(i915, &i915->gpu_error.test_irq_rings, val);
>  }
>
>  DEFINE_SIMPLE_ATTRIBUTE(i915_ring_test_irq_fops,
>

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

Regards,

Tvrtko
Chris Wilson March 6, 2017, 9:03 p.m. UTC | #2
On Mon, Mar 06, 2017 at 05:45:30PM +0000, Tvrtko Ursulin wrote:
> 
> On 06/03/2017 10:15, Chris Wilson wrote:
> > static int
> >+fault_irq_set(struct drm_i915_private *i915, unsigned long *irq, u64 val)
> >+{
> >+	int err;
> >+
> >+	err = mutex_lock_interruptible(&i915->drm.struct_mutex);
> >+	if (err)
> >+		return err;
> >+
> >+	err = i915_gem_wait_for_idle(i915,
> >+				     I915_WAIT_LOCKED |
> >+				     I915_WAIT_INTERRUPTIBLE);
> >+	if (err)
> >+		goto err_unlock;
> >+
> >+	/* Retire to kick idle work */
> >+	i915_gem_retire_requests(i915);
> >+	GEM_BUG_ON(i915->gt.active_requests);
> >+
> >+	*irq = val & INTEL_INFO(i915)->ring_mask;
> 
> Looks like a type width mismatch on 32-bit.
> 
> Should we change missed_irq_rings to an u64?

Currently unsigned long, and for convenience with test_bit() should
remain as an array of unsigned longs (i.e. bitmap). The mismatch here is
probably better served by s/u64 val/unsigned long val/. If we need to go
a full bitmap in the future, we'll have to switch to a bitmap_parse_str.
So unsigned long looks to be the future proof type.

> 
> >+	mutex_unlock(&i915->drm.struct_mutex);
> >+
> >+	/* Flush idle worker to disarm irq */
> >+	while (flush_delayed_work(&i915->gt.idle_work))
> >+		;
> 
> Worth sticking a schedule in here or something? Not worth it for
> debugfs I guess since we don't have it elsewhere.

flush_delayed_work() is itself a schedule (if active), underneath it
does a wait-for-completion on the work.
-Chris
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 4a3e5b9552f8..511d3541d3d5 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -4138,6 +4138,39 @@  DEFINE_SIMPLE_ATTRIBUTE(i915_wedged_fops,
 			"%llu\n");
 
 static int
+fault_irq_set(struct drm_i915_private *i915, unsigned long *irq, u64 val)
+{
+	int err;
+
+	err = mutex_lock_interruptible(&i915->drm.struct_mutex);
+	if (err)
+		return err;
+
+	err = i915_gem_wait_for_idle(i915,
+				     I915_WAIT_LOCKED |
+				     I915_WAIT_INTERRUPTIBLE);
+	if (err)
+		goto err_unlock;
+
+	/* Retire to kick idle work */
+	i915_gem_retire_requests(i915);
+	GEM_BUG_ON(i915->gt.active_requests);
+
+	*irq = val & INTEL_INFO(i915)->ring_mask;
+	mutex_unlock(&i915->drm.struct_mutex);
+
+	/* Flush idle worker to disarm irq */
+	while (flush_delayed_work(&i915->gt.idle_work))
+		;
+
+	return 0;
+
+err_unlock:
+	mutex_unlock(&i915->drm.struct_mutex);
+	return err;
+}
+
+static int
 i915_ring_missed_irq_get(void *data, u64 *val)
 {
 	struct drm_i915_private *dev_priv = data;
@@ -4149,18 +4182,8 @@  i915_ring_missed_irq_get(void *data, u64 *val)
 static int
 i915_ring_missed_irq_set(void *data, u64 val)
 {
-	struct drm_i915_private *dev_priv = data;
-	struct drm_device *dev = &dev_priv->drm;
-	int ret;
-
-	/* Lock against concurrent debugfs callers */
-	ret = mutex_lock_interruptible(&dev->struct_mutex);
-	if (ret)
-		return ret;
-	dev_priv->gpu_error.missed_irq_rings = val;
-	mutex_unlock(&dev->struct_mutex);
-
-	return 0;
+	struct drm_i915_private *i915 = data;
+	return fault_irq_set(i915, &i915->gpu_error.missed_irq_rings, val);
 }
 
 DEFINE_SIMPLE_ATTRIBUTE(i915_ring_missed_irq_fops,
@@ -4180,13 +4203,11 @@  i915_ring_test_irq_get(void *data, u64 *val)
 static int
 i915_ring_test_irq_set(void *data, u64 val)
 {
-	struct drm_i915_private *dev_priv = data;
+	struct drm_i915_private *i915 = data;
 
-	val &= INTEL_INFO(dev_priv)->ring_mask;
+	val &= INTEL_INFO(i915)->ring_mask;
 	DRM_DEBUG_DRIVER("Masking interrupts on rings 0x%08llx\n", val);
-	dev_priv->gpu_error.test_irq_rings = val;
-
-	return 0;
+	return fault_irq_set(i915, &i915->gpu_error.test_irq_rings, val);
 }
 
 DEFINE_SIMPLE_ATTRIBUTE(i915_ring_test_irq_fops,