linux-stable.git/drivers/gpu/drm/sysfb/drm_sysfb_modeset.c, branch linux-rolling-lts

drm/sysfb: Remove double assignment to pointer crtc_state

2025-09-04T07:26:39+00:00

The declaration of pointer crtc_state includes an assignment to
crtc_state. The double assignment of crtc_state is redundant and
can be removed.

Fixes: 061963cd9e5b ("drm/sysfb: Blit to CRTC destination format")
Signed-off-by: Colin Ian King 
Reviewed-by: Thomas Zimmermann 
Signed-off-by: Thomas Zimmermann 
Link: https://lore.kernel.org/r/20250903083106.2703580-1-colin.i.king@gmail.com

drm/sysfb: Do not deref unexisting CRTC state in atomic_disable

2025-08-27T12:09:58+00:00

Do not access CRTC state in drm_sysfb_plane_helper_atomic_disable().
Use format from sysfb device for clearing scanout buffer. This is
the behavior from before commit 061963cd9e5b ("drm/sysfb: Blit to
CRTC destination format").

When being disabled, the plane has no associated CRTC. Trying to deref
the format pointer results in a segmentation fault. An example stack
track is shown below.

[   58.948915] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000023: 0000 [#1] SMP KASAN PTI
[   58.959971] KASAN: null-ptr-deref in range [0x0000000000000118-0x000000000000011f]
[...]
[   58.979308] RIP: 0010:drm_sysfb_plane_helper_atomic_disable+0x1af/0x520
[...]
[   59.084227] Call Trace:
[   59.086682]  
[   59.088793]  ? __pfx_drm_sysfb_plane_helper_atomic_disable+0x10/0x10
[   59.095155]  ? crtc_disable+0xf2/0x5a0
[   59.098920]  drm_atomic_helper_commit_planes+0x848/0x1030
[   59.104336]  drm_atomic_helper_commit_tail+0x41/0xb0
[   59.109316]  commit_tail+0x204/0x330
[   59.112903]  drm_atomic_helper_commit+0x242/0x2e0
[   59.117618]  ? __pfx_drm_atomic_helper_commit+0x10/0x10
[   59.122851]  drm_atomic_commit+0x1e1/0x290
[   59.126957]  ? drm_atomic_add_affected_connectors+0x266/0x330
[   59.132714]  ? __pfx_drm_atomic_commit+0x10/0x10
[   59.137343]  ? __pfx___drm_printfn_info+0x10/0x10
[   59.142058]  ? drm_atomic_set_crtc_for_connector+0x436/0x630
[   59.147729]  atomic_remove_fb+0x631/0x920
[   59.151751]  ? save_trace+0xcf/0x180
[   59.155343]  ? __pfx_atomic_remove_fb+0x10/0x10
[   59.159890]  ? __pfx___drm_dev_dbg+0x10/0x10
[   59.164173]  drm_framebuffer_remove+0x19a/0x710

Signed-off-by: Thomas Zimmermann 
Fixes: 061963cd9e5b ("drm/sysfb: Blit to CRTC destination format")
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/14874
Cc: Thomas Zimmermann 
Cc: Javier Martinez Canillas 
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Maarten Lankhorst 
Link: https://lore.kernel.org/r/20250826145044.954396-1-tzimmermann@suse.de

drm/sysfb: Blit to CRTC destination format

2025-08-26T07:54:17+00:00

Use the color format stored in struct drm_sysfb_crtc_state for
color-format conversion instead of the scanout-buffer format
announced by firmware. Currently, both values are identical.

This will allow drivers to modify the CRTC's input format to a
certain extend. Specifically, vesadrm will be able to display RGB
framebuffers when the scanout buffer is of C8 format. With color-
format conversion to RGB332 and correct setup of the C8 palette,
displaying XRGB8888-based buffers under C8 can be achieved.

v2:
- refer to RGB332 as CRTC input format

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Javier Martinez Canillas 
Link: https://lore.kernel.org/r/20250714151513.309475-5-tzimmermann@suse.de

drm/format-helper: Move drm_fb_build_fourcc_list() to sysfb helpers

2025-06-18T08:46:03+00:00

Only sysfb drivers use drm_fb_build_fourcc_list(). Move the function
to sysfb helpers and rename it accordingly. Update drivers and tests.

v3:
- update naming in tests
v2:
- select DRM_SYSFB_HELPER (kernel test robot)

Signed-off-by: Thomas Zimmermann 
Reviewed-by: José Expósito 
Acked-by: Maxime Ripard 
Acked-by: Javier Martinez Canillas 
Link: https://lore.kernel.org/r/20250616083846.221396-4-tzimmermann@suse.de

drm/sysfb: Split source file

2025-04-14T08:16:12+00:00

Split drm_sysfb_helper.c into two source files. There's now one
source file for the mode-setting pipeline and one source file for
module meta data. Prepares for adding additional source code to
sysfb helpers.

v2:
- fix typo in commit message (Javier)

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Javier Martinez Canillas 
Link: https://lore.kernel.org/r/20250410083834.10810-2-tzimmermann@suse.de