[Intel-gfx] [PATCH 2/4] drm/i915: Fix context/engine cleanup order

[Daniel Vetter]

On Thu, Jan 21, 2016 at 07:37:45PM +0000, Dave Gordon wrote:
> From: Nick Hoath <nicholas.hoath at intel.com>
> 
> Swap the order of context & engine cleanup, so that contexts are cleaned
> up first, and *then* engines. This is a more sensible order anyway, but
> in particular has become necessary since the 'intel_ring_initialized()
> must be simple and inline' patch, which now uses ring->dev as an
> 'initialised' flag, so it can now be NULL after engine teardown. This
> in turn can cause a problem in the context code, which (used to) check
> the ring->dev->struct_mutex -- causing a fault if ring->dev was NULL.
> 
> Also rename the cleanup function to reflect what it actually does
> (cleanup engines, not a ringbuffer), and fix an annoying whitespace issue.
> 
> v2: Also make the fix in i915_load_modeset_init, not just in
>     i915_driver_unload (Chris Wilson)
> v3: Had extra stuff in it.
> v4: Reverted extra stuff (so we're back to v2).
>     Rebased and updated commentary above (Dave Gordon).
> 
> Signed-off-by: Nick Hoath <nicholas.hoath at intel.com>
> Signed-off-by: Dave Gordon <david.s.gordon at intel.com>
> Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk> (v2)

Trusting that v2==v4 and applied it.
-Daniel

> 
> Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> 
> ---
>  drivers/gpu/drm/i915/i915_dma.c |  4 ++--
>  drivers/gpu/drm/i915/i915_drv.h |  2 +-
>  drivers/gpu/drm/i915/i915_gem.c | 23 ++++++++++++-----------
>  3 files changed, 15 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
> index d70d96f..4725e8d 100644
> --- a/drivers/gpu/drm/i915/i915_dma.c
> +++ b/drivers/gpu/drm/i915/i915_dma.c
> @@ -451,8 +451,8 @@ static int i915_load_modeset_init(struct drm_device *dev)
>  
>  cleanup_gem:
>  	mutex_lock(&dev->struct_mutex);
> -	i915_gem_cleanup_ringbuffer(dev);
>  	i915_gem_context_fini(dev);
> +	i915_gem_cleanup_engines(dev);
>  	mutex_unlock(&dev->struct_mutex);
>  cleanup_irq:
>  	intel_guc_ucode_fini(dev);
> @@ -1196,8 +1196,8 @@ int i915_driver_unload(struct drm_device *dev)
>  
>  	intel_guc_ucode_fini(dev);
>  	mutex_lock(&dev->struct_mutex);
> -	i915_gem_cleanup_ringbuffer(dev);
>  	i915_gem_context_fini(dev);
> +	i915_gem_cleanup_engines(dev);
>  	mutex_unlock(&dev->struct_mutex);
>  	intel_fbc_cleanup_cfb(dev_priv);
>  	i915_gem_cleanup_stolen(dev);
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 204661f..021e88a 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -3012,7 +3012,7 @@ int i915_gem_init_rings(struct drm_device *dev);
>  int __must_check i915_gem_init_hw(struct drm_device *dev);
>  int i915_gem_l3_remap(struct drm_i915_gem_request *req, int slice);
>  void i915_gem_init_swizzling(struct drm_device *dev);
> -void i915_gem_cleanup_ringbuffer(struct drm_device *dev);
> +void i915_gem_cleanup_engines(struct drm_device *dev);
>  int __must_check i915_gpu_idle(struct drm_device *dev);
>  int __must_check i915_gem_suspend(struct drm_device *dev);
>  void __i915_add_request(struct drm_i915_gem_request *req,
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 371bbb2..799a53a 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -4912,7 +4912,7 @@ int i915_gem_init_rings(struct drm_device *dev)
>  		req = i915_gem_request_alloc(ring, NULL);
>  		if (IS_ERR(req)) {
>  			ret = PTR_ERR(req);
> -			i915_gem_cleanup_ringbuffer(dev);
> +			i915_gem_cleanup_engines(dev);
>  			goto out;
>  		}
>  
> @@ -4925,7 +4925,7 @@ int i915_gem_init_rings(struct drm_device *dev)
>  		if (ret && ret != -EIO) {
>  			DRM_ERROR("PPGTT enable ring #%d failed %d\n", i, ret);
>  			i915_gem_request_cancel(req);
> -			i915_gem_cleanup_ringbuffer(dev);
> +			i915_gem_cleanup_engines(dev);
>  			goto out;
>  		}
>  
> @@ -4933,7 +4933,7 @@ int i915_gem_init_rings(struct drm_device *dev)
>  		if (ret && ret != -EIO) {
>  			DRM_ERROR("Context enable ring #%d failed %d\n", i, ret);
>  			i915_gem_request_cancel(req);
> -			i915_gem_cleanup_ringbuffer(dev);
> +			i915_gem_cleanup_engines(dev);
>  			goto out;
>  		}
>  
> @@ -5008,7 +5008,7 @@ int i915_gem_init(struct drm_device *dev)
>  }
>  
>  void
> -i915_gem_cleanup_ringbuffer(struct drm_device *dev)
> +i915_gem_cleanup_engines(struct drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  	struct intel_engine_cs *ring;
> @@ -5017,13 +5017,14 @@ int i915_gem_init(struct drm_device *dev)
>  	for_each_ring(ring, dev_priv, i)
>  		dev_priv->gt.cleanup_ring(ring);
>  
> -    if (i915.enable_execlists)
> -            /*
> -             * Neither the BIOS, ourselves or any other kernel
> -             * expects the system to be in execlists mode on startup,
> -             * so we need to reset the GPU back to legacy mode.
> -             */
> -            intel_gpu_reset(dev);
> +	if (i915.enable_execlists) {
> +		/*
> +		 * Neither the BIOS, ourselves or any other kernel
> +		 * expects the system to be in execlists mode on startup,
> +		 * so we need to reset the GPU back to legacy mode.
> +		 */
> +		intel_gpu_reset(dev);
> +	}
>  }
>  
>  static void
> -- 
> 1.9.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch