linux.git/drivers/gpu/drm/sysfb, branch nocache-cleanup

drm/sysfb: Remove duplicate declarations

2026-01-14T10:03:56+00:00

Commit 6046b49bafff ("drm/sysfb: Share helpers for integer validation")
and commit e8c086880b2b ("drm/sysfb: Share helpers for screen_info
validation") added duplicate function declarations. Remove the latter
ones.

Signed-off-by: Thomas Zimmermann 
Fixes: e8c086880b2b ("drm/sysfb: Share helpers for screen_info validation")
Cc: Thomas Zimmermann 
Cc: Javier Martinez Canillas 
Cc: dri-devel@lists.freedesktop.org
Cc:  # v6.16+
Reviewed-by: Javier Martinez Canillas 
Link: https://patch.msgid.link/20260108145058.56943-7-tzimmermann@suse.de

drm: include drm_print.h where needed

2025-10-31T08:34:52+00:00

There are a gazillion files that depend on drm_print.h being indirectly
included via drm_buddy.h, drm_mm.h, or ttm/ttm_resource.h. In
preparation for removing those includes, explicitly include drm_print.h
where needed.

Cc: Thomas Zimmermann 
Reviewed-by: Thomas Zimmermann 
Signed-off-by: Jani Nikula 
Link: https://lore.kernel.org/r/5fe67395907be33eb5199ea6d540e29fddee71c8.1761734313.git.jani.nikula@intel.com

drm/sysfb: Use new CRTC state in begin_fb_access

2025-10-23T08:36:14+00:00

Retrieve the CRTC's new state with drm_atomic_get_new_crtc_state()
in drm_sysfb_plane_helper_begin_fb_access(). The blit function might
be incorrect otherwise.

Signed-off-by: Thomas Zimmermann 
Fixes: cb71de092553 ("drm/sysfb: Lookup blit function during atomic check")
Reported-by: Ville Syrjälä 
Closes: https://lore.kernel.org/dri-devel/aPJrs7_u8KcalNsC@intel.com/
Cc: Thomas Zimmermann 
Cc: Javier Martinez Canillas 
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Javier Martinez Canillas 
Link: https://lore.kernel.org/r/20251020125227.41308-1-tzimmermann@suse.de

drm/sysfb: simpledrm: Sort headers correctly

2025-09-23T13:59:01+00:00

Make sure the headers are sorted alphabetically to ensure consistent
code.

Signed-off-by: Luca Weiss 
Reviewed-by: Javier Martinez Canillas 
Reviewed-by: Thomas Zimmermann 
Signed-off-by: Thomas Zimmermann

drm/sysfb: Lookup blit function during atomic check

2025-09-23T13:06:06+00:00

Some configurations of sysfb outputs require format conversion from
framebuffer to scanout buffer. It is a driver bug if the conversion
helper is missing, yet it might happen on odd scanout formats. The old
code, based on drm_fb_blit(), only detects this situation during the
commit's hardware update, which is too late to abort the update.

Lookup the correct blit helper as part of the check phase. Then store
it in the sysfb plane state. Allows for detection of a missing helper
before the commit has started. Also avoids drm_fb_blit()'s large switch
statement on each updated scanline. Only a single lookup has to be done.

The lookup is in drm_sysfb_get_blit_func(), which only tracks formats
supported by sysfb drivers.

The lookup happens in sysfb's begin_fb_access helper instead of its
atomic_check helper. This allows vesadrm, and possibly other drivers,
to implement their own atomic_check without interfering with blit
lookups. Vesadrm implements XRGB8888 on top of R8 formats with the
help of the atomic_check. Doing the blit lookup in begin_fb_access then
always uses the correct CRTC format on all drivers.

v2:
- vesadrm: use drm_sysfb_plane_helper_begin_fb_access()
- fix type in commit description (Javier)

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Javier Martinez Canillas 
Link: https://lore.kernel.org/r/20250918154207.84714-3-tzimmermann@suse.de

drm/sysfb: Add custom plane state

2025-09-23T13:06:05+00:00

The plane-state type struct drm_sysfb_plane_state will store the
helper for blitting to the scanout buffer.

v2:
- add variable for duplicated shadow-plane state (Javier)
- fix build error

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Javier Martinez Canillas 
Link: https://lore.kernel.org/r/20250918154207.84714-2-tzimmermann@suse.de

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/vesadrm: Remove unneeded semicolon

2025-08-28T10:15:14+00:00

Remove unnecessary semicolons reported by Coccinelle/coccicheck and the
semantic patch at scripts/coccinelle/misc/semicolon.cocci.

Signed-off-by: Chen Ni 
Reviewed-by: Thomas Zimmermann 
Signed-off-by: Thomas Zimmermann 
Link: https://lore.kernel.org/r/20250828085708.3383760-1-nichen@iscas.ac.cn

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/vesadrm: Support DRM_FORMAT_C8

2025-08-26T07:54:20+00:00

Add support for DRM_FORMAT_C8 to vesadrm. The new pixel-format
description PIXEL_FORMAT_C8 describes the layout. Vesadrm's helpers
vesadrm_fill_palette_lut() and vesadrm_load_palette_lut() set the
hardware palette according to the CRTC's output format.

The driver emulates XRGB8888 by converting the source buffer to
RGB332 and using the resulting 256 colors as index into the hardware
palette. The hardware palette converts back to RGB during scanout.
This has no overhead compared to other format conversion, but allows
common userspace, such as Wayland compositors, to operate on the
display.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Javier Martinez Canillas 
Link: https://lore.kernel.org/r/20250714151513.309475-10-tzimmermann@suse.de