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

[Chris Wilson]

Quoting Tvrtko Ursulin (2019-09-25 13:43:46)
> 
> 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?

Because the overlay used struct_mutex, now it does not.
-Chris