[Intel-gfx] [PATCH] drm/i915: Extend rpm wakelock during i915_handle_error()

[Michel Thierry]

On 3/14/2017 10:18 AM, Chris Wilson wrote:
> We take the runtime pm wakelock during i915_handle_error() to ensure
> that all paths that reach the error capture keep the device awake during
> the hw reads. However, we need to extend that from the reset handler to
> include the earlier capture routines.
>
> Reported-by: Antonio Argenziano <antonio.argenziano at intel.com>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Michel Thierry <michel.thierry at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_irq.c | 25 ++++++++++++++-----------
>  1 file changed, 14 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 31f0d7c8992f..52e1fe8a98fb 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -2664,14 +2664,6 @@ static void i915_reset_and_wakeup(struct drm_i915_private *dev_priv)
>  	DRM_DEBUG_DRIVER("resetting chip\n");
>  	kobject_uevent_env(kobj, KOBJ_CHANGE, reset_event);
>
> -	/*
> -	 * In most cases it's guaranteed that we get here with an RPM
> -	 * reference held, for example because there is a pending GPU
> -	 * request that won't finish until the reset is done. This
> -	 * isn't the case at least when we get here by doing a
> -	 * simulated reset via debugs, so get an RPM reference.
> -	 */
> -	intel_runtime_pm_get(dev_priv);
>  	intel_prepare_reset(dev_priv);
>
>  	do {
> @@ -2693,7 +2685,6 @@ static void i915_reset_and_wakeup(struct drm_i915_private *dev_priv)
>  				     HZ));
>
>  	intel_finish_reset(dev_priv);
> -	intel_runtime_pm_put(dev_priv);
>
>  	if (!test_bit(I915_WEDGED, &dev_priv->gpu_error.flags))
>  		kobject_uevent_env(kobj,
> @@ -2780,15 +2771,24 @@ void i915_handle_error(struct drm_i915_private *dev_priv,
>  	vscnprintf(error_msg, sizeof(error_msg), fmt, args);
>  	va_end(args);
>
> +	/*
> +	 * In most cases it's guaranteed that we get here with an RPM
> +	 * reference held, for example because there is a pending GPU
> +	 * request that won't finish until the reset is done. This
> +	 * isn't the case at least when we get here by doing a
> +	 * simulated reset via debugfs, so get an RPM reference.
> +	 */
> +	intel_runtime_pm_get(dev_priv);
> +
>  	i915_capture_error_state(dev_priv, engine_mask, error_msg);
>  	i915_clear_error_registers(dev_priv);
>
>  	if (!engine_mask)
> -		return;
> +		goto out;
>
>  	if (test_and_set_bit(I915_RESET_IN_PROGRESS,
>  			     &dev_priv->gpu_error.flags))
> -		return;
> +		goto out;
>
>  	/*
>  	 * Wakeup waiting processes so that the reset function
> @@ -2805,6 +2805,9 @@ void i915_handle_error(struct drm_i915_private *dev_priv,
>  	i915_error_wake_up(dev_priv);
>
>  	i915_reset_and_wakeup(dev_priv);
> +
> +out:
> +	intel_runtime_pm_put(dev_priv);
>  }
>
>  /* Called from drm generic code, passed 'crtc' which
>

Reviewed-by: Michel Thierry <michel.thierry at intel.com>