From e8450f51a4b39cfe0878b4aee339820b2bfff240 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Fri, 25 Jul 2014 23:34:03 +0200 Subject: [PATCH] drm/irq: Implement a generic vblank_wait function MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit As usual in both a crtc index and a struct drm_crtc * version. The function assumes that no one drivers their display below 10Hz, and it will complain if the vblank wait takes longer than that. v2: Also check dev->max_vblank_counter since some drivers register a fake get_vblank_counter function. v3: Use drm_vblank_count instead of calling the low-level ->get_vblank_counter callback. That way we'll get the sw-cooked counter for platforms without proper vblank support and so can ditch the max_vblank_counter check again. v4: Review from Michel Dänzer: - Restore lost notes about v3: - Spelling in kerneldoc. - Inline wait_event condition. - s/vblank_wait/wait_one_vblank/ Cc: Michel Dänzer Cc: Ville Syrjälä Reviewed-by: Michel Dänzer Reviewed-by: Matt Roper Signed-off-by: Daniel Vetter --- drivers/gpu/drm/drm_irq.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ include/drm/drmP.h | 2 ++ 2 files changed, 46 insertions(+) diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 6f16a104d6d0..e64d24951fc2 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -1010,6 +1010,50 @@ void drm_crtc_vblank_put(struct drm_crtc *crtc) EXPORT_SYMBOL(drm_crtc_vblank_put); /** + * drm_wait_one_vblank - wait for one vblank + * @dev: DRM device + * @crtc: crtc index + * + * This waits for one vblank to pass on @crtc, using the irq driver interfaces. + * It is a failure to call this when the vblank irq for @crtc is disabled, e.g. + * due to lack of driver support or because the crtc is off. + */ +void drm_wait_one_vblank(struct drm_device *dev, int crtc) +{ + int ret; + u32 last; + + ret = drm_vblank_get(dev, crtc); + if (WARN_ON(ret)) + return; + + last = drm_vblank_count(dev, crtc); + + ret = wait_event_timeout(dev->vblank[crtc].queue, + last != drm_vblank_count(dev, crtc), + msecs_to_jiffies(100)); + + WARN_ON(ret == 0); + + drm_vblank_put(dev, crtc); +} +EXPORT_SYMBOL(drm_wait_one_vblank); + +/** + * drm_crtc_wait_one_vblank - wait for one vblank + * @crtc: DRM crtc + * + * This waits for one vblank to pass on @crtc, using the irq driver interfaces. + * It is a failure to call this when the vblank irq for @crtc is disabled, e.g. + * due to lack of driver support or because the crtc is off. + */ +void drm_crtc_wait_one_vblank(struct drm_crtc *crtc) +{ + drm_wait_one_vblank(crtc->dev, drm_crtc_index(crtc)); +} +EXPORT_SYMBOL(drm_crtc_wait_one_vblank); + +/** * drm_vblank_off - disable vblank events on a CRTC * @dev: DRM device * @crtc: CRTC in question diff --git a/include/drm/drmP.h b/include/drm/drmP.h index d3d9be6b83ef..c2209178981f 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -1327,6 +1327,8 @@ extern int drm_vblank_get(struct drm_device *dev, int crtc); extern void drm_vblank_put(struct drm_device *dev, int crtc); extern int drm_crtc_vblank_get(struct drm_crtc *crtc); extern void drm_crtc_vblank_put(struct drm_crtc *crtc); +extern void drm_wait_one_vblank(struct drm_device *dev, int crtc); +extern void drm_crtc_wait_one_vblank(struct drm_crtc *crtc); extern void drm_vblank_off(struct drm_device *dev, int crtc); extern void drm_vblank_on(struct drm_device *dev, int crtc); extern void drm_crtc_vblank_off(struct drm_crtc *crtc); -- 2.11.0