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

[Tvrtko Ursulin]

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 at 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 at intel.com>

Regards,

Tvrtko