On 3/23/26 15:27, [email protected] wrote:
From: Leo Li <[email protected]>
Add and use an drm internal helper to check if vblanks have been turned
off (via drm_crtc_vblank_off()) for a CRTC, rather than relying on the
return value of drm_crtc_vblank_get().
This is in preparation of introducing deferred vblank enable/disable, as
vblank_get() will not return the expected error code when the driver
defers vblank enable.
No functional change is intended.
I have two trivial nits below, you can include my tag with next version
or just fix them when committing if everything else turns out reviewed OK.
Reviewed-by: Mario Limonciello (AMD) <[email protected]>
Signed-off-by: Leo Li <[email protected]>
---
drivers/gpu/drm/drm_atomic_helper.c | 11 +++++------
drivers/gpu/drm/drm_internal.h | 1 +
drivers/gpu/drm/drm_vblank.c | 17 +++++++++++++++++
3 files changed, 23 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c
b/drivers/gpu/drm/drm_atomic_helper.c
index 26953ed6b53e8..102937e3ff35b 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -48,6 +48,7 @@
#include "drm_crtc_helper_internal.h"
#include "drm_crtc_internal.h"
+#include "drm_internal.h"
/**
* DOC: overview
@@ -1259,7 +1260,7 @@ drm_atomic_helper_commit_crtc_disable(struct drm_device
*dev, struct drm_atomic_
for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
const struct drm_crtc_helper_funcs *funcs;
- int ret;
+ bool vblank_off;
/* Shut down everything that needs a full modeset. */
if (!drm_atomic_crtc_needs_modeset(new_crtc_state))
@@ -1287,19 +1288,17 @@ drm_atomic_helper_commit_crtc_disable(struct drm_device
*dev, struct drm_atomic_
if (!drm_dev_has_vblank(dev))
continue;
- ret = drm_crtc_vblank_get(crtc);
+ vblank_off = drm_crtc_vblank_is_off(crtc);
/*
* Self-refresh is not a true "disable"; ensure vblank remains
* enabled.
*/
if (new_crtc_state->self_refresh_active)
- WARN_ONCE(ret != 0,
+ WARN_ONCE(vblank_off,
"driver disabled vblank in self-refresh\n");
else
- WARN_ONCE(ret != -EINVAL,
+ WARN_ONCE(!vblank_off,
"driver forgot to call
drm_crtc_vblank_off()\n");
- if (ret == 0)
- drm_crtc_vblank_put(crtc);
}
}
EXPORT_SYMBOL(drm_atomic_helper_commit_crtc_disable);
diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h
index f893b1e3a596e..7d10515fe2ed5 100644
--- a/drivers/gpu/drm/drm_internal.h
+++ b/drivers/gpu/drm/drm_internal.h
@@ -131,6 +131,7 @@ static inline void drm_vblank_destroy_worker(struct
drm_vblank_crtc *vblank)
int drm_vblank_worker_init(struct drm_vblank_crtc *vblank);
void drm_vblank_cancel_pending_works(struct drm_vblank_crtc *vblank);
void drm_handle_vblank_works(struct drm_vblank_crtc *vblank);
+bool drm_crtc_vblank_is_off(struct drm_crtc *crtc);
/* IOCTLS */
int drm_wait_vblank_ioctl(struct drm_device *dev, void *data,
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index f78bf37f1e0a7..983c131b23694 100644
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -2318,3 +2318,20 @@ void drm_crtc_vblank_get_vblank_timeout(struct drm_crtc
*crtc, ktime_t *vblank_t
*vblank_time = ktime_sub(*vblank_time, vtimer->interval);
}
EXPORT_SYMBOL(drm_crtc_vblank_get_vblank_timeout);
+
+/**
+ * drm_crtc_vblank_is_off - check if vblank is off on a CRTC
+ * @crtc: CRTC in question
+ *
+ * Return true if vblanks is currently turned off via drm_crtc_vblank_off().
+ * Return False otherwise.
nit1: you should be consistent with case of true/False
nit2: vblank not vblanks
+ */
+bool drm_crtc_vblank_is_off(struct drm_crtc *crtc)
+{
+ struct drm_vblank_crtc *vblank = drm_crtc_vblank_crtc(crtc);
+
+ /* Spinlock adds the necessary barriers */
+ guard(spinlock_irqsave)(&crtc->dev->vbl_lock);
+ return vblank->inmodeset && !vblank->enabled;
+}
+EXPORT_SYMBOL(drm_crtc_vblank_is_off);
