On Wed, Jul 30, 2014 at 05:36:21PM +0300, Ville Syrjälä wrote:
On Wed, Jul 30, 2014 at 04:20:25PM +0200, Thierry Reding wrote:
On Wed, Jul 30, 2014 at 05:32:28PM +0900, Michel Dänzer wrote:
On 30.07.2014 17:22, Daniel Vetter wrote:
On Wed, Jul 30, 2014 at 11:59:33AM +0900, Michel Dänzer wrote:
On 30.07.2014 06:32, Daniel Vetter wrote:
- due to lack of driver support or because the crtc is off.
- */
+void drm_crtc_vblank_wait(struct drm_crtc *crtc) +{
- drm_vblank_wait(crtc->dev, drm_crtc_index(crtc));
+} +EXPORT_SYMBOL(drm_crtc_vblank_wait);
+/**
Maybe the function names should be *_vblank_wait_next() or something to clarify the purpose and reduce potential confusion versus drm_wait_vblank().
Yeah that name is just transferred from the i915 driver. What about drm_wait_one_vblank()/drm_crtc_wait_one_vblank()?
I don't care that much :), go ahead.
Just my two cents: our downstream kernel has a helper somewhat like this which waits for a specified number of frames (apparently this is useful for some panels that require up to 5 or 6 frames before they display the correct image on screen). So perhaps something like this could work:
void drm_wait_vblank_count(struct drm_device *dev, unsigned int crtc, unsigned int count) { u32 last; int ret;
ret = drm_vblank_get(dev, crtc); if (WARN_ON(ret)) return; while (count--) { last = drm_vblank_count(dev, crtc); ... } drm_vblank_put(dev, crtc);}
Would be nicer to wait for an absolute vblank count instead IMO. Or if you want to pass a relative count in just convert it to an absolute count first and wait for it (taking wraparound into account obviously).
Yeah I've conisidered to to a generic version, but don't though about all the ways I'll get wrap-around wrong and decided that we better postpone this until there's a real need. We can easily extract it later on ... -Daniel