Re: [Linaro-mm-sig] [PATCH v8 11/11] drm: sti: Add DRM driver itself

On Wed, Jul 30, 2014 at 7:42 PM, Benjamin Gaignard benjamin.gaignard@linaro.org wrote:

+static int sti_drm_crtc_page_flip(struct drm_crtc *crtc,

•                             struct drm_framebuffer *fb,
  

•                             struct drm_pending_vblank_event *event,
  

•                             uint32_t page_flip_flags)
  

+{

•   struct drm_device *drm_dev = crtc->dev;
  

•   struct drm_framebuffer *old_fb;
  

•   struct sti_mixer *mixer = to_sti_mixer(crtc);
  

•   unsigned long flags;
  

•   int ret;
  

•   DRM_DEBUG_KMS("fb %d --> fb %d\n",
  

•                   crtc->primary->fb->base.id, fb->base.id);
  

•   mutex_lock(&drm_dev->struct_mutex);
  

struct_mutex locking here is pure cargo-cult. Please remove asap. -Daniel

•   old_fb = crtc->primary->fb;
  

•   crtc->primary->fb = fb;
  

•   ret = sti_drm_crtc_mode_set_base(crtc, crtc->x, crtc->y, old_fb);
  

•   if (ret) {
  

•           DRM_ERROR("failed\n");
  

•           crtc->primary->fb = old_fb;
  

•           goto out;
  

•   }
  

•   if (event) {
  

•           event->pipe = mixer->id;
  

•           ret = drm_vblank_get(drm_dev, event->pipe);
  

•           if (ret) {
  

•                   DRM_ERROR("Cannot get vblank\n");
  

•                   goto out;
  

•           }
  

•           spin_lock_irqsave(&drm_dev->event_lock, flags);
  

•           if (mixer->pending_event) {
  

•                   drm_vblank_put(drm_dev, event->pipe);
  

•                   ret = -EBUSY;
  

•           } else {
  

•                   mixer->pending_event = event;
  

•           }
  

•           spin_unlock_irqrestore(&drm_dev->event_lock, flags);
  

•   }
  

+out:

•   mutex_unlock(&drm_dev->struct_mutex);
  

•   return ret;
  

+}