Merge tag 'drm-misc-next-2025-10-02' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-next

drm-misc-next for v6.19:

UAPI Changes:

Cross-subsystem Changes:
-  fbcon cleanups.
- Make drivers depend on FB_TILEBLITTING instead of selecting it,
  and hide FB_MODE_HELPERS.

Core Changes:
- More preparations for rust.
- Throttle dirty worker with vblank
- Use drm_for_each_bridge_in_chain_scoped in drm's bridge code and
  assorted fixes.
- Ensure drm_client_modeset tests are enabled in UML.
- Rename ttm_bo_put to ttm_bo_fini, as a further step in removing the
  TTM bo refcount.
- Add POST_LT_ADJ_REQ training sequence.
- Show list of removed but still allocated bridges.
- Add a simulated vblank interrupt for hardware without it,
  and add some helpers to use them in vkms and hypervdrm.

Driver Changes:
- Assorted small fixes, cleanups and updates to host1x, tegra,
  panthor,   amdxdna, gud, vc4, ssd130x, ivpu, panfrost, panthor,
  sysfb, bridge/sn65dsi86, solomon, ast, tidss.
- Convert drivers from using .round_rate() to .determine_rate()
- Add support for KD116N3730A07/A12, chromebook mt8189, JT101TM023,
  LQ079L1SX01, raspberrypi 5" panels.
- Improve reclocking on tegra186+ with nouveau.
- Improve runtime pm in amdxdna.
- Add support for HTX_PAI in imx.
- Use a helper to calculate dumb buffer sizes in most drivers.

Signed-off-by: Simona Vetter <simona.vetter@ffwll.ch>
From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://lore.kernel.org/r/b412fb91-8545-466a-8102-d89c0f2758a7@linux.intel.com

1 files changed, 44 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_client_modeset.c b/drivers/gpu/drm/drm_client_modeset.c
index 9c2c3b0c8c47..fc4caf7da5fc 100644
--- a/drivers/gpu/drm/drm_client_modeset.c
+++ b/drivers/gpu/drm/drm_client_modeset.c
@@ -1293,6 +1293,50 @@ int drm_client_modeset_dpms(struct drm_client_dev *client, int mode)
 }
 EXPORT_SYMBOL(drm_client_modeset_dpms);
 
+/**
+ * drm_client_modeset_wait_for_vblank() - Wait for the next VBLANK to occur
+ * @client: DRM client
+ * @crtc_index: The ndex of the CRTC to wait on
+ *
+ * Block the caller until the given CRTC has seen a VBLANK. Do nothing
+ * if the CRTC is disabled. If there's another DRM master present, fail
+ * with -EBUSY.
+ *
+ * Returns:
+ * 0 on success, or negative error code otherwise.
+ */
+int drm_client_modeset_wait_for_vblank(struct drm_client_dev *client, unsigned int crtc_index)
+{
+	struct drm_device *dev = client->dev;
+	struct drm_crtc *crtc;
+	int ret;
+
+	/*
+	 * Rate-limit update frequency to vblank. If there's a DRM master
+	 * present, it could interfere while we're waiting for the vblank
+	 * event. Don't wait in this case.
+	 */
+	if (!drm_master_internal_acquire(dev))
+		return -EBUSY;
+
+	crtc = client->modesets[crtc_index].crtc;
+
+	/*
+	 * Only wait for a vblank event if the CRTC is enabled, otherwise
+	 * just don't do anything, not even report an error.
+	 */
+	ret = drm_crtc_vblank_get(crtc);
+	if (!ret) {
+		drm_crtc_wait_one_vblank(crtc);
+		drm_crtc_vblank_put(crtc);
+	}
+
+	drm_master_internal_release(dev);
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_client_modeset_wait_for_vblank);
+
 #ifdef CONFIG_DRM_KUNIT_TEST
 #include "tests/drm_client_modeset_test.c"
 #endif