[Intel-gfx] [PATCH 22/27] drm/i915/overlay: Drop struct_mutex guard

[Tvrtko Ursulin]

On 25/09/2019 11:01, Chris Wilson wrote:
> The overlay uses the modeset mutex to control itself and only required
> the struct_mutex for requests, which is now obsolete.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   drivers/gpu/drm/i915/display/intel_display.c |  7 +------
>   drivers/gpu/drm/i915/display/intel_overlay.c | 13 -------------
>   drivers/gpu/drm/i915/gt/intel_reset.c        |  4 ----
>   3 files changed, 1 insertion(+), 23 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 99ddbb7bedbc..038f14d9b5c9 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -5738,13 +5738,8 @@ void hsw_disable_ips(const struct intel_crtc_state *crtc_state)
>   
>   static void intel_crtc_dpms_overlay_disable(struct intel_crtc *intel_crtc)
>   {
> -	if (intel_crtc->overlay) {
> -		struct drm_device *dev = intel_crtc->base.dev;
> -
> -		mutex_lock(&dev->struct_mutex);
> +	if (intel_crtc->overlay)
>   		(void) intel_overlay_switch_off(intel_crtc->overlay);
> -		mutex_unlock(&dev->struct_mutex);
> -	}
>   
>   	/* Let userspace switch the overlay on again. In most cases userspace
>   	 * has to recompute where to put it anyway.
> diff --git a/drivers/gpu/drm/i915/display/intel_overlay.c b/drivers/gpu/drm/i915/display/intel_overlay.c
> index e12e1a753af0..daea112cbb87 100644
> --- a/drivers/gpu/drm/i915/display/intel_overlay.c
> +++ b/drivers/gpu/drm/i915/display/intel_overlay.c
> @@ -439,8 +439,6 @@ static int intel_overlay_release_old_vid(struct intel_overlay *overlay)
>   	struct i915_request *rq;
>   	u32 *cs;
>   
> -	lockdep_assert_held(&dev_priv->drm.struct_mutex);
> -
>   	/*
>   	 * Only wait if there is actually an old frame to release to
>   	 * guarantee forward progress.
> @@ -751,7 +749,6 @@ static int intel_overlay_do_put_image(struct intel_overlay *overlay,
>   	struct i915_vma *vma;
>   	int ret, tmp_width;
>   
> -	lockdep_assert_held(&dev_priv->drm.struct_mutex);
>   	WARN_ON(!drm_modeset_is_locked(&dev_priv->drm.mode_config.connection_mutex));
>   
>   	ret = intel_overlay_release_old_vid(overlay);
> @@ -852,7 +849,6 @@ int intel_overlay_switch_off(struct intel_overlay *overlay)
>   	struct drm_i915_private *dev_priv = overlay->i915;
>   	int ret;
>   
> -	lockdep_assert_held(&dev_priv->drm.struct_mutex);
>   	WARN_ON(!drm_modeset_is_locked(&dev_priv->drm.mode_config.connection_mutex));
>   
>   	ret = intel_overlay_recover_from_interrupt(overlay);
> @@ -1068,11 +1064,7 @@ int intel_overlay_put_image_ioctl(struct drm_device *dev, void *data,
>   
>   	if (!(params->flags & I915_OVERLAY_ENABLE)) {
>   		drm_modeset_lock_all(dev);
> -		mutex_lock(&dev->struct_mutex);
> -
>   		ret = intel_overlay_switch_off(overlay);
> -
> -		mutex_unlock(&dev->struct_mutex);
>   		drm_modeset_unlock_all(dev);
>   
>   		return ret;
> @@ -1088,7 +1080,6 @@ int intel_overlay_put_image_ioctl(struct drm_device *dev, void *data,
>   		return -ENOENT;
>   
>   	drm_modeset_lock_all(dev);
> -	mutex_lock(&dev->struct_mutex);
>   
>   	if (i915_gem_object_is_tiled(new_bo)) {
>   		DRM_DEBUG_KMS("buffer used for overlay image can not be tiled\n");
> @@ -1152,14 +1143,12 @@ int intel_overlay_put_image_ioctl(struct drm_device *dev, void *data,
>   	if (ret != 0)
>   		goto out_unlock;
>   
> -	mutex_unlock(&dev->struct_mutex);
>   	drm_modeset_unlock_all(dev);
>   	i915_gem_object_put(new_bo);
>   
>   	return 0;
>   
>   out_unlock:
> -	mutex_unlock(&dev->struct_mutex);
>   	drm_modeset_unlock_all(dev);
>   	i915_gem_object_put(new_bo);
>   
> @@ -1233,7 +1222,6 @@ int intel_overlay_attrs_ioctl(struct drm_device *dev, void *data,
>   	}
>   
>   	drm_modeset_lock_all(dev);
> -	mutex_lock(&dev->struct_mutex);
>   
>   	ret = -EINVAL;
>   	if (!(attrs->flags & I915_OVERLAY_UPDATE_ATTRS)) {
> @@ -1290,7 +1278,6 @@ int intel_overlay_attrs_ioctl(struct drm_device *dev, void *data,
>   
>   	ret = 0;
>   out_unlock:
> -	mutex_unlock(&dev->struct_mutex);
>   	drm_modeset_unlock_all(dev);
>   
>   	return ret;
> diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c b/drivers/gpu/drm/i915/gt/intel_reset.c
> index 2685c0103e90..ee0c5c24282c 100644
> --- a/drivers/gpu/drm/i915/gt/intel_reset.c
> +++ b/drivers/gpu/drm/i915/gt/intel_reset.c
> @@ -1265,10 +1265,6 @@ int intel_gt_terminally_wedged(struct intel_gt *gt)
>   	if (!test_bit(I915_RESET_BACKOFF, &gt->reset.flags))
>   		return -EIO;
>   
> -	/* XXX intel_reset_finish() still takes struct_mutex!!! */
> -	if (mutex_is_locked(&gt->i915->drm.struct_mutex))
> -		return -EAGAIN;
> -

What is this hunk doing here?

Regards,

Tvrtko

>   	if (wait_event_interruptible(gt->reset.queue,
>   				     !test_bit(I915_RESET_BACKOFF,
>   					       &gt->reset.flags)))
>