Re: [PATCH v2 2/2] drm/i915: sanitize RPS resetting during GPU reset

[Daniel Vetter <daniel@ffwll.ch>]

On Thu, Dec 04, 2014 at 02:59:32PM +0200, Imre Deak wrote:
> Atm, we don't disable RPS interrupts and related work items before
> resetting the GPU. This may interfere with the following GPU
> initialization and cause RPS interrupts to show up in PM_IIR too early
> before calling gen6_enable_rps_interrupts() (triggering a WARN there).
> 
> Solve this by disabling RPS interrupts and flushing any related work
> items before resetting the GPU.
> 
> v2:
> - split out the common parts of the gt suspend and the new gt reset
>   functions (Paulo)
> 
> Reported-by: He, Shuang <shuang.he@intel.com>
> Testcase: igt/gem_reset_stats/ban-render
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=86644
> Signed-off-by: Imre Deak <imre.deak@intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.c |  5 ++++-
>  drivers/gpu/drm/i915/intel_pm.c | 28 +++++++++++++++++++---------
>  2 files changed, 23 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 71be3c9..8377249 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -810,6 +810,9 @@ int i915_reset(struct drm_device *dev)
>  	if (!i915.reset)
>  		return 0;
>  
> +	if (drm_core_check_feature(dev, DRIVER_MODESET))
> +		intel_reset_gt_powersave(dev);

UMS support is dead, so you can leave this hunk out.
-Daniel

> +
>  	mutex_lock(&dev->struct_mutex);
>  
>  	i915_gem_reset(dev);
> @@ -881,7 +884,7 @@ int i915_reset(struct drm_device *dev)
>  		 * of re-init after reset.
>  		 */
>  		if (INTEL_INFO(dev)->gen > 5)
> -			intel_reset_gt_powersave(dev);
> +			intel_enable_gt_powersave(dev);
>  	} else {
>  		mutex_unlock(&dev->struct_mutex);
>  	}
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 78911e2..45c786f 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -6072,6 +6072,20 @@ void intel_cleanup_gt_powersave(struct drm_device *dev)
>  		valleyview_cleanup_gt_powersave(dev);
>  }
>  
> +static void gen6_suspend_rps(struct drm_device *dev)
> +{
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +
> +	flush_delayed_work(&dev_priv->rps.delayed_resume_work);
> +
> +	/*
> +	 * TODO: disable RPS interrupts on GEN9+ too once RPS support
> +	 * is added for it.
> +	 */
> +	if (INTEL_INFO(dev)->gen < 9)
> +		gen6_disable_rps_interrupts(dev);
> +}
> +
>  /**
>   * intel_suspend_gt_powersave - suspend PM work and helper threads
>   * @dev: drm device
> @@ -6087,14 +6101,7 @@ void intel_suspend_gt_powersave(struct drm_device *dev)
>  	if (INTEL_INFO(dev)->gen < 6)
>  		return;
>  
> -	flush_delayed_work(&dev_priv->rps.delayed_resume_work);
> -
> -	/*
> -	 * TODO: disable RPS interrupts on GEN9+ too once RPS support
> -	 * is added for it.
> -	 */
> -	if (INTEL_INFO(dev)->gen < 9)
> -		gen6_disable_rps_interrupts(dev);
> +	gen6_suspend_rps(dev);
>  
>  	/* Force GPU to min freq during suspend */
>  	gen6_rps_idle(dev_priv);
> @@ -6197,8 +6204,11 @@ void intel_reset_gt_powersave(struct drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  
> +	if (INTEL_INFO(dev)->gen < 6)
> +		return;
> +
> +	gen6_suspend_rps(dev);
>  	dev_priv->rps.enabled = false;
> -	intel_enable_gt_powersave(dev);
>  }
>  
>  static void ibx_init_clock_gating(struct drm_device *dev)
> -- 
> 1.8.4
> 
> _______________________________________________
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> Intel-gfx@lists.freedesktop.org
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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