Merge tag 'drm-misc-next-2025-02-12' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-next

drm-misc-next for v6.15:

UAPI Changes:

fourcc:
- Add modifiers for MediaTek tiled formats

Cross-subsystem Changes:

bus:
- mhi: Enable image transfer via BHIe in PBL

dma-buf:
- Add fast-path for single-fence merging

Core Changes:

atomic helper:
- Allow full modeset on connector changes
- Clarify semantics of allow_modeset
- Clarify semantics of drm_atomic_helper_check()

buddy allocator:
- Fix multi-root cleanup

ci:
- Update IGT

display:
- dp: Support Extendeds Wake Timeout
- dp_mst: Fix RAD-to-string conversion

panic:
- Encode QR code according to Fido 2.2

probe helper:
- Cleanups

scheduler:
- Cleanups

ttm:
- Refactor pool-allocation code
- Cleanups

Driver Changes:

amdxdma:
- Fix error handling
- Cleanups

ast:
- Refactor detection of transmitter chips
- Refactor support of VBIOS display-mode handling
- astdp: Fix connection status; Filter unsupported display modes

bridge:
- adv7511: Report correct capabilities
- it6505: Fix HDCP V compare
- sn65dsi86: Fix device IDs
- Cleanups

i915:
- Enable Extendeds Wake Timeout

imagination:
- Check job dependencies with DRM-sched helper

ivpu:
- Improve command-queue handling
- Use workqueue for IRQ handling
- Add suport for HW fault injection
- Locking fixes
- Cleanups

mgag200:
- Add support for G200eH5 chips

msm:
- dpu: Add concurrent writeback support for DPU 10.x+

nouveau:
- Move drm_slave_encoder interface into driver
- nvkm: Refactor GSP RPC

omapdrm:
- Cleanups

panel:
- Convert several panels to multi-style functions to improve error
  handling
- edp: Add support for B140UAN04.4, BOE NV140FHM-NZ, CSW MNB601LS1-3,
  LG LP079QX1-SP0V, MNE007QS3-7, STA 116QHD024002, Starry 116KHD024006,
  Lenovo T14s Gen6 Snapdragon
- himax-hx83102: Add support for CSOT PNA957QT1-1, Kingdisplay
  kd110n11-51ie, Starry 2082109qfh040022-50e

panthor:
- Expose sizes of intenral BOs via fdinfo
- Fix race between reset and suspend
- Cleanups

qaic:
- Add support for AIC200
- Cleanups

renesas:
- Fix limits in DT bindings

rockchip:
- rk3576: Add HDMI support
- vop2: Add new display modes on RK3588 HDMI0 up to 4K
- Don't change HDMI reference clock rate
- Fix DT bindings

solomon:
- Set SPI device table to silence warnings
- Fix pixel and scanline encoding

v3d:
- Cleanups

vc4:
- Use drm_exec
- Use dma-resv for wait-BO ioctl
- Remove seqno infrastructure

virtgpu:
- Support partial mappings of GEM objects
- Reserve VGA resources during initialization
- Fix UAF in virtgpu_dma_buf_free_obj()
- Add panic support

vkms:
- Switch to a managed modesetting pipeline
- Add support for ARGB8888

xlnx:
- Set correct DMA segment size
- Fix error handling
- Fix docs

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20250212090625.GA24865@linux.fritz.box

1 files changed, 21 insertions, 2 deletions

diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index 31ca88deb10d..1ded9a8d4e84 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -376,8 +376,27 @@ struct drm_atomic_state {
 	 *
 	 * Allow full modeset. This is used by the ATOMIC IOCTL handler to
 	 * implement the DRM_MODE_ATOMIC_ALLOW_MODESET flag. Drivers should
-	 * never consult this flag, instead looking at the output of
-	 * drm_atomic_crtc_needs_modeset().
+	 * generally not consult this flag, but instead look at the output of
+	 * drm_atomic_crtc_needs_modeset(). The detailed rules are:
+	 *
+	 * - Drivers must not consult @allow_modeset in the atomic commit path.
+	 *   Use drm_atomic_crtc_needs_modeset() instead.
+	 *
+	 * - Drivers must consult @allow_modeset before adding unrelated struct
+	 *   drm_crtc_state to this commit by calling
+	 *   drm_atomic_get_crtc_state(). See also the warning in the
+	 *   documentation for that function.
+	 *
+	 * - Drivers must never change this flag, it is under the exclusive
+	 *   control of userspace.
+	 *
+	 * - Drivers may consult @allow_modeset in the atomic check path, if
+	 *   they have the choice between an optimal hardware configuration
+	 *   which requires a modeset, and a less optimal configuration which
+	 *   can be committed without a modeset. An example would be suboptimal
+	 *   scanout FIFO allocation resulting in increased idle power
+	 *   consumption. This allows userspace to avoid flickering and delays
+	 *   for the normal composition loop at reasonable cost.
 	 */
 	bool allow_modeset : 1;
 	/**