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.
Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
---
drivers/gpu/drm/drm_irq.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
include/drm/drmP.h | 2 ++
2 files changed, 47 insertions(+)
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 0de123afdb34..76024fdde452 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -999,6 +999,51 @@ void drm_crtc_vblank_put(struct drm_crtc *crtc)
EXPORT_SYMBOL(drm_crtc_vblank_put);
/**
+ * drm_vblank_wait - 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 disable, e.g.
+ * due to lack of driver support or because the crtc is off.
+ */
+void drm_vblank_wait(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);
+
+#define C (last != drm_vblank_count(dev, crtc))
+ ret = wait_event_timeout(dev->vblank[crtc].queue,
+ C, msecs_to_jiffies(100));
+
+ WARN_ON(ret == 0);
+#undef C
+
+ drm_vblank_put(dev, crtc);
+}
+EXPORT_SYMBOL(drm_vblank_wait);
+
+/**
+ * drm_crtc_vblank_wait - 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 disable, e.g.
+ * 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);
+
+/**
* 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 06a673894c47..f72e5ef5f7b0 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1355,6 +1355,8 @@ 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_vblank_wait(struct drm_device *dev, int crtc);
+extern void drm_crtc_vblank_wait(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);
--
2.0.1
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