linux/drivers/gpu/drm/sysfb, branch v6.16

drm/vesadrm: Avoid NULL-ptr deref in vesadrm_pmi_cmap_write()

2025-06-27T14:00:49Z

Only set PMI fields if the screen_info's Vesa PM segment has been set. Vesa PMI is the power-management interface. It also provides means to set the color palette. The interface is optional, so not all VESA graphics cards support it. Print vesafb's warning [1] if the hardware palette cannot be set at all. If unsupported the field PrimaryPalette in struct vesadrm.pmi is NULL, which results in a segmentation fault. Happens with qemu's Cirrus emulation. Signed-off-by: Thomas Zimmermann Fixes: 814d270b31d2 ("drm/sysfb: vesadrm: Add gamma correction") Link: https://elixir.bootlin.com/linux/v6.15/source/drivers/video/fbdev/vesafb.c#L375 # 1 Cc: Thomas Zimmermann Cc: Javier Martinez Canillas Cc: dri-devel@lists.freedesktop.org Acked-by: Javier Martinez Canillas Link: https://lore.kernel.org/r/20250617140944.142392-1-tzimmermann@suse.de

drm/sysfb: Share helpers for screen_info validation

2025-04-14T08:16:14Z

Share efidrm's and vesadrm's validation of struct screen_info in shared helpers. Update the drivers. Most validation helpers test individual values against limits and can be shared as they are. For color formats, a common helper looks up the correct DRM format info from a driver-provided list of color formats. These screen_info helpers are only available if CONFIG_SCREEN_INFO has been selected, as done by efidrm and vesadrm. Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Link: https://lore.kernel.org/r/20250410083834.10810-4-tzimmermann@suse.de

drm/sysfb: Share helpers for integer validation

2025-04-14T08:16:13Z

Provide sysfb helpers for validating framebuffer integer values against limits. Update drivers. If a driver did not specify a limit for a certain value, use INT_MAX. v2: - declare module information near EOF (Javier) Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Link: https://lore.kernel.org/r/20250410083834.10810-3-tzimmermann@suse.de

drm/sysfb: Split source file

2025-04-14T08:16:12Z

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

drm/sysfb: efidrm: Avoid clang -Wsometimes-uninitialized in efidrm_device_create()

2025-04-11T13:28:59Z

Clang warns (or errors with CONFIG_WERROR=y): drivers/gpu/drm/sysfb/efidrm.c:353:11: error: variable 'screen_base' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized] 353 | else if (mem_flags & EFI_MEMORY_WB) | ^~~~~~~~~~~~~~~~~~~~~~~~~ drivers/gpu/drm/sysfb/efidrm.c:356:7: note: uninitialized use occurs here 356 | if (!screen_base) | ^~~~~~~~~~~ drivers/gpu/drm/sysfb/efidrm.c:353:7: note: remove the 'if' if its condition is always true 353 | else if (mem_flags & EFI_MEMORY_WB) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 354 | screen_base = devm_memremap(&pdev->dev, mem->start, resource_size(mem), drivers/gpu/drm/sysfb/efidrm.c:261:27: note: initialize the variable 'screen_base' to silence this warning 261 | void __iomem *screen_base; | ^ | = NULL efidrm_get_mem_flags() can only return a mask that has at least one of the tested values set so the else case is impossible but clang's static analysis runs before inlining so it cannot know that. Initialize screen_base to NULL and add a defensive error message in case mem_flags were ever returned without one of the four valid values. Fixes: 32ae90c66fb6 ("drm/sysfb: Add efidrm for EFI displays") Reviewed-by: Thomas Zimmermann Signed-off-by: Nathan Chancellor Signed-off-by: Thomas Zimmermann Link: https://lore.kernel.org/r/20250410-efidrm-avoid-uninit-screen_info-warning-v2-1-b79646f58c24@kernel.org

drm/sysfb: efidrm: Support module builds

2025-04-09T07:03:15Z

Make CONFIG_DRM_EFIDRM a tristate to enable module builds. Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Link: https://lore.kernel.org/r/20250408091837.407401-3-tzimmermann@suse.de

drm/sysfb: simpledrm: Remove unused helper simpledrm_device_of_dev()

2025-04-08T07:11:41Z

After moving most of the mode-setting pipeline into drm_sysfb_helper.c, simpledrm_device_of_dev() is no longer being used. Remove it. Signed-off-by: Thomas Zimmermann Reported-by: Jocelyn Falempe Closes: https://lore.kernel.org/dri-devel/20250407131344.139878-1-jfalempe@redhat.com/ Fixes: 177dfbdb7e67 ("drm/sysfb: Merge primary-plane functions") Reviewed-by: Javier Martinez Canillas Reviewed-by: Jocelyn Falempe Link: https://lore.kernel.org/r/20250407134753.985925-3-tzimmermann@suse.de

drm/simpledrm: Do not upcast in release helpers

2025-04-08T07:11:40Z

The res pointer passed to simpledrm_device_release_clocks() and simpledrm_device_release_regulators() points to an instance of struct simpledrm_device. No need to upcast from struct drm_device. The upcast is harmless, as DRM device is the first field in struct simpledrm_device. Signed-off-by: Thomas Zimmermann Fixes: 11e8f5fd223b ("drm: Add simpledrm driver") Cc: # v5.14+ Reviewed-by: Javier Martinez Canillas Reviewed-by: Jocelyn Falempe Link: https://lore.kernel.org/r/20250407134753.985925-2-tzimmermann@suse.de

drm/sysfb: vesadrm: Add gamma correction

2025-04-07T09:02:07Z

Add palette support and export GAMMA properties via sysfs. User-space compositors can use this interface for programming gamma ramps or night mode. Vesadrm supports palette updates via VGA DAC registers or VESA palette calls. Up to 256 palette entries are available. Userspace always supplies gamma ramps of 256 entries. If the native color format does not match this because pixel component have less then 8 bits, vesadrm interpolates among the palette entries. The code uses CamelCase style in a few places to match the VESA manuals. v3: - fix coding style v2: - use CONFIG_X86_32 instead of __i386__ (checkpatch) - protect struct vesadrm.pmi with CONFIG_X86_32 Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Link: https://lore.kernel.org/r/20250401094056.32904-19-tzimmermann@suse.de

drm/sysfb: vesadrm: Add EDID support

2025-04-07T09:02:07Z

Enable the connector's EDID property if edid_info contains valid data. Exports the EDID via sysfs for user-space compositors. EDID information is not always available. Depending on the system and kernel configuration, it is either provided by the boot loader or read by the kernel during early boot stages. There's only one VESA display, so EDID data always belongs to this output. Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Link: https://lore.kernel.org/r/20250401094056.32904-18-tzimmermann@suse.de