Re: [PATCH RFC v3 0/3] Add splash DRM client

[Mario Limonciello]

On 5/10/26 16:29, Francesco Valla wrote:
> Hello,
>
> this is the third (and hopefully last) RFC version for the DRM-based
> splash screen.
>
> Motivation behind the work can be found in v1 [0]; in a nutshell, the
> splash DRM client can draw a splashscreen using:
>
>    - the BMP image supplied by the EFI BGRT;
>    - a BMP image loaded as firmware (either built-in or loaded from the
>      filesystem);
>    - a colored background.
>
> This revision greatly simplifies the image seletion logic; now the EFI
> BGRT is always used as first source if enabled, with a fallback to BMP
> image loaded as firmware and then to a plain color.
>
> Sanity checks on the EFI BGRT image have been borrowed from the efifb
> driver. More complete splash providers (e.g.: Plymouth) have an
> extensive management of platform-specific quirks, but I don't think it
> would be reasonable to introduce such complexity here.
>
> Additional notes:
>    - Rotation is still not managed (and probably won't?).
>    - Support for tiled screens is untested.
>    - Plain color and BMP sources were tested on QEMU, Beagleplay and
>      i.MX93 FRDM.
>    - EFI BGRT support was tested using QEMU+OVMF.
>
> Thank you in advance for any feedback.

Unfortunately I found that I couldn't compile with my normal Kconfig.

ERROR: modpost: "bgrt_tab" [drivers/gpu/drm/clients/drm_client_lib.ko] 
undefined!
ERROR: modpost: "bgrt_image_size" 
[drivers/gpu/drm/clients/drm_client_lib.ko] undefined!
make[2]: *** [scripts/Makefile.modpost:147: Module.symvers] Error 1
make[1]: *** [/home/supermario/src/linux/Makefile:2091: modpost] Error 2
make: *** [Makefile:248: __sub-make] Error 2

❮ grep ^CONFIG_DRM .config
CONFIG_DRM=y
CONFIG_DRM_KMS_HELPER=m
CONFIG_DRM_DRAW=y
CONFIG_DRM_CLIENT=y
CONFIG_DRM_CLIENT_LIB=m
CONFIG_DRM_CLIENT_SELECTION=m
CONFIG_DRM_CLIENT_SETUP=y
CONFIG_DRM_FBDEV_EMULATION=y
CONFIG_DRM_FBDEV_OVERALLOC=100
CONFIG_DRM_CLIENT_SPLASH=y
CONFIG_DRM_CLIENT_SPLASH_BACKGROUND_COLOR=0x000000
CONFIG_DRM_CLIENT_SPLASH_SRC_BGRT=y
CONFIG_DRM_CLIENT_SPLASH_BMP_SUPPORT=y
CONFIG_DRM_CLIENT_DEFAULT_SPLASH=y
CONFIG_DRM_CLIENT_DEFAULT="splash"
CONFIG_DRM_LOAD_EDID_FIRMWARE=y
CONFIG_DRM_DISPLAY_HELPER=m
CONFIG_DRM_DISPLAY_DP_AUX_CHARDEV=y
CONFIG_DRM_DISPLAY_DP_HELPER=y
CONFIG_DRM_DISPLAY_DSC_HELPER=y
CONFIG_DRM_DISPLAY_HDCP_HELPER=y
CONFIG_DRM_DISPLAY_HDMI_CEC_NOTIFIER_HELPER=y
CONFIG_DRM_DISPLAY_HDMI_HELPER=y
CONFIG_DRM_TTM=m
CONFIG_DRM_EXEC=m
CONFIG_DRM_BUDDY=m
CONFIG_DRM_TTM_HELPER=m
CONFIG_DRM_GEM_SHMEM_HELPER=m
CONFIG_DRM_SUBALLOC_HELPER=m
CONFIG_DRM_SCHED=m
CONFIG_DRM_PANEL_BACKLIGHT_QUIRKS=m
CONFIG_DRM_PRIVACY_SCREEN=y
CONFIG_DRM_AMDGPU=m
CONFIG_DRM_AMDGPU_CIK=y
CONFIG_DRM_AMDGPU_USERPTR=y
CONFIG_DRM_AMD_ISP=y
CONFIG_DRM_AMD_ACP=y
CONFIG_DRM_AMD_DC=y
CONFIG_DRM_AMD_DC_FP=y
CONFIG_DRM_AMD_SECURE_DISPLAY=y
CONFIG_DRM_BRIDGE=y
CONFIG_DRM_PANEL_BRIDGE=y
CONFIG_DRM_PANEL=y
CONFIG_DRM_SYSFB_HELPER=m
CONFIG_DRM_SIMPLEDRM=m
CONFIG_DRM_PANEL_ORIENTATION_QUIRKS=y
CONFIG_DRM_ACCEL=y
CONFIG_DRM_ACCEL_AMDXDNA=m
CONFIG_DRM_ACCEL_HABANALABS=m
CONFIG_DRM_ACCEL_IVPU=m
CONFIG_DRM_ACCEL_QAIC=m
❮ grep BGRT .config
CONFIG_ACPI_BGRT=y
CONFIG_DRM_CLIENT_SPLASH_SRC_BGRT=y

> Best regards,
> Francesco
>
> [0] https://lore.kernel.org/all/20251027-drm_client_splash-v1-0-00698933b34a@xxxxxxxx
>
> Signed-off-by: Francesco Valla <francesco@xxxxxxxx>
> ---
> Changes in v3:
>    - Simplified the image selection and management logic, with direct
>      fallback from EFI BGRT to MP as firmware
>    - Used new drm_draw_can_convert_from_xrgb8888() API
>    - Added proper get_unaligned_ calls for EFI BGRT access
>    - Fixed Kconfig dependencies
>    - Link to v2: https://lore.kernel.org/r/20260106-drm_client_splash-v2-0-6e86a7434b59@xxxxxxxx
>
> Changes in v2:
>    - Moved from raw dump to BMP format for static image source
>    - Removed support for configurable message
>    - Removed support for progress bar
>    - Added EFI BGRT as image source
> Link to v1: https://lore.kernel.org/r/20251027-drm_client_splash-v1-0-00698933b34a@xxxxxxxx
>
> To: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> To: Maxime Ripard <mripard@xxxxxxxxxx>
> To: Thomas Zimmermann <tzimmermann@xxxxxxx>
> To: David Airlie <airlied@xxxxxxxxx>
> To: Simona Vetter <simona@xxxxxxxx>
> To: Francesco Valla <francesco@xxxxxxxx>
> To: Jonathan Corbet <corbet@xxxxxxx>
> To: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Cc: linux-doc@xxxxxxxxxxxxxxx
>
> ---
> Francesco Valla (3):
>        drm: client: add splash client
>        MAINTAINERS: add entry for DRM splash client
>        drm: docs: remove bootsplash from TODO
>
>   Documentation/gpu/todo.rst                    |  17 -
>   MAINTAINERS                                   |   7 +
>   drivers/gpu/drm/clients/Kconfig               |  63 +-
>   drivers/gpu/drm/clients/Makefile              |   1 +
>   drivers/gpu/drm/clients/drm_client_internal.h |   9 +
>   drivers/gpu/drm/clients/drm_client_setup.c    |   8 +
>   drivers/gpu/drm/clients/drm_splash.c          | 932 ++++++++++++++++++++++++++
>   7 files changed, 1019 insertions(+), 18 deletions(-)
> ---
> base-commit: afaa0a477099cb7256e26fe11289c753a225ac97
> change-id: 20251026-drm_client_splash-e10d7d663e7f
>
> Best regards,
> --
> Francesco Valla <francesco@xxxxxxxx>