linux-toradex.git/arch/x86/video, branch master

x86/video: Only fall back to vga_default_device() without screen info

2026-07-07T15:14:55+00:00

Some multi GPU systems may have a VGA compatible device, but that might not be
used for display.  If due to enumeration order this device is found before the
one actually used for display then multiple devices may show the boot_display
attribute, confusing userspace.

When screen info is valid, use it exclusively to find the primary device so
that only the device backing the framebuffer is reported.  Only when no
framebuffer has been set up does it make sense to fall back to the default VGA
device.  This ensures at most one primary graphics device, preferably the one
with the framebuffer.

Fixes: ad90860bd10ee ("fbcon: Use screen info to find primary device")
Closes: https://lore.kernel.org/linux-pci/20260618081803.2790848-1-aaron.ma@canonical.com/#t
Reported-by: Aaron Ma 
Suggested-by: Thomas Zimmermann 
Signed-off-by: Mario Limonciello 
Signed-off-by: Borislav Petkov (AMD) 
Reviewed-by: Thomas Zimmermann 
Tested-by: Aaron Ma 
Cc: 
Link: https://patch.msgid.link/20260623141505.1816786-1-mario.limonciello@amd.com

sysfb: Replace screen_info with sysfb_primary_display

2025-12-16T13:12:44+00:00

Replace the global screen_info with sysfb_primary_display of type
struct sysfb_display_info. Adapt all users of screen_info.

Instances of screen_info are defined for x86, loongarch and EFI,
with only one instance compiled into a specific build. Replace all
of them with sysfb_primary_display.

All existing users of screen_info are updated by pointing them to
sysfb_primary_display.screen instead. This introduces some churn to
the code, but has no impact on functionality.

Boot parameters and EFI config tables are unchanged. They transfer
screen_info as before. The logic in EFI's alloc_screen_info() changes
slightly, as it now returns the screen field of sysfb_primary_display.

Signed-off-by: Thomas Zimmermann 
Acked-by: Arnd Bergmann 
Acked-by: Ard Biesheuvel 
Acked-by: Bjorn Helgaas  # drivers/pci/
Reviewed-by: Richard Lyu 
Signed-off-by: Ard Biesheuvel

fbcon: Use screen info to find primary device

2025-09-10T14:35:33+00:00

On systems with non VGA GPUs fbcon can't find the primary GPU because
video_is_primary_device() only checks the VGA arbiter.

Add a screen info check to video_is_primary_device() so that callers
can get accurate data on such systems.

Reviewed-by: Thomas Zimmermann 
Suggested-by: Thomas Zimmermann 
Suggested-by: Bjorn Helgaas 
Reviewed-by: Bjorn Helgaas 
Link: https://lore.kernel.org/r/20250811162606.587759-4-superm1@kernel.org
Signed-off-by: Mario Limonciello (AMD)

arch: Fix name collision with ACPI's video.o

2024-05-20T21:17:06+00:00

Commit 2fd001cd3600 ("arch: Rename fbdev header and source files")
renames the video source files under arch/ such that they do not
refer to fbdev any longer. The new files named video.o conflict with
ACPI's video.ko module. Modprobing the ACPI module can then fail with
warnings about missing symbols, as shown below.

  (i915_selftest:1107) igt_kmod-WARNING: i915: Unknown symbol acpi_video_unregister (err -2)
  (i915_selftest:1107) igt_kmod-WARNING: i915: Unknown symbol acpi_video_register_backlight (err -2)
  (i915_selftest:1107) igt_kmod-WARNING: i915: Unknown symbol __acpi_video_get_backlight_type (err -2)
  (i915_selftest:1107) igt_kmod-WARNING: i915: Unknown symbol acpi_video_register (err -2)

Fix the issue by renaming the architecture's video.o to video-common.o.

Reported-by: Chaitanya Kumar Borah 
Closes: https://lore.kernel.org/intel-gfx/9dcac6e9-a3bf-4ace-bbdc-f697f767f9e0@suse.de/T/#t
Signed-off-by: Thomas Zimmermann 
Fixes: 2fd001cd3600 ("arch: Rename fbdev header and source files")
Reviewed-by: Hans de Goede 
Cc: Arnd Bergmann 
Cc: linux-arch@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Arnd Bergmann

arch: Rename fbdev header and source files

2024-05-03T15:07:50+00:00

The per-architecture fbdev code has no dependencies on fbdev and can
be used for any video-related subsystem. Rename the files to 'video'.
Use video-sti.c on parisc as the source file depends on CONFIG_STI_CORE.

On arc, arm, arm64, sh, and um the asm header file is an empty wrapper
around the file in asm-generic. Let Kbuild generate the file. The build
system does this automatically. Only um needs to generate video.h
explicitly, so that it overrides the host architecture's header. The
latter would otherwise interfere with the build.

Further update all includes statements, include guards, and Makefiles.
Also update a few strings and comments to refer to video instead of
fbdev.

v3:
- arc, arm, arm64, sh: generate asm header via build system (Sam,
Helge, Arnd)
- um: rename fb.h to video.h
- fix typo in commit message (Sam)

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Sam Ravnborg 
Cc: Vineet Gupta 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Huacai Chen 
Cc: WANG Xuerui 
Cc: Geert Uytterhoeven 
Cc: Thomas Bogendoerfer 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Yoshinori Sato 
Cc: Rich Felker 
Cc: John Paul Adrian Glaubitz 
Cc: "David S. Miller" 
Cc: Andreas Larsson 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: x86@kernel.org
Cc: "H. Peter Anvin" 
Signed-off-by: Arnd Bergmann

arch: Remove struct fb_info from video helpers

2024-05-03T15:07:50+00:00

The per-architecture video helpers do not depend on struct fb_info
or anything else from fbdev. Remove it from the interface and replace
fb_is_primary_device() with video_is_primary_device(). The new helper
is similar in functionality, but can operate on non-fbdev devices.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Sam Ravnborg 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: "David S. Miller" 
Cc: Andreas Larsson 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: x86@kernel.org
Cc: "H. Peter Anvin" 
Signed-off-by: Arnd Bergmann

arch: Select fbdev helpers with CONFIG_VIDEO

2024-05-03T15:07:50+00:00

Various Kconfig options selected the per-architecture helpers for
fbdev. But none of the contained code depends on fbdev. Standardize
on CONFIG_VIDEO, which will allow to add more general helpers for
video functionality.

CONFIG_VIDEO protects each architecture's video/ directory. This
allows for the use of more fine-grained control for each directory's
files, such as the use of CONFIG_STI_CORE on parisc.

v2:
- sparc: rebased onto Makefile changes

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Sam Ravnborg 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: "David S. Miller" 
Cc: Andreas Larsson 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: x86@kernel.org
Cc: "H. Peter Anvin" 
Signed-off-by: Arnd Bergmann

fbdev: Replace fb_pgprotect() with pgprot_framebuffer()

2023-10-12T07:20:46+00:00

Rename the fbdev mmap helper fb_pgprotect() to pgprot_framebuffer().
The helper sets VMA page-access flags for framebuffers in device I/O
memory.

Also clean up the helper's parameters and return value. Instead of
the VMA instance, pass the individial parameters separately: existing
page-access flags, the VMAs start and end addresses and the offset
in the underlying device memory rsp file. Return the new page-access
flags. These changes align pgprot_framebuffer() with other pgprot_()
functions.

v4:
	* fix commit message (Christophe)
v3:
	* rename fb_pgprotect() to pgprot_framebuffer() (Arnd)

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Arnd Bergmann 
Acked-by: Geert Uytterhoeven  # m68k
Reviewed-by: Javier Martinez Canillas 
Link: https://patchwork.freedesktop.org/patch/msgid/20230922080636.26762-3-tzimmermann@suse.de

Merge drm/drm-next into drm-misc-next

2023-07-24T13:44:47+00:00

Backmerging to get v6.5-rc2.

Signed-off-by: Thomas Zimmermann

fbdev: Split frame buffer support in FB and FB_CORE symbols

2023-07-22T10:25:04+00:00

Currently the CONFIG_FB option has to be enabled even if no legacy fbdev
drivers are needed (e.g: only to have support for framebuffer consoles).

The DRM subsystem has a fbdev emulation layer, but depends on CONFIG_FB
and so it can only be enabled if that dependency is enabled as well.

That means fbdev drivers have to be explicitly disabled if users want to
enable CONFIG_FB, only to use fbcon and/or the DRM fbdev emulation layer.

This patch introduces a non-visible CONFIG_FB_CORE symbol that could be
enabled just to have core support needed for CONFIG_DRM_FBDEV_EMULATION,
allowing CONFIG_FB to be disabled (and automatically disabling all the
fbdev drivers).

Nothing from fb_backlight.o and fbmon.o is used by the DRM fbdev emulation
layer so these two objects can be compiled out when CONFIG_FB is disabled.

Signed-off-by: Javier Martinez Canillas 
Reviewed-by: Arnd Bergmann 
Tested-by: Arnd Bergmann 
Acked-by: Helge Deller 
Link: https://patchwork.freedesktop.org/patch/msgid/20230719081544.741051-4-javierm@redhat.com