kernel/linux.git/drivers/gpu/drm/tegra/fbdev.c, branch v7.2-rc1

drm/tegra: fbdev: Use a DRM client buffer

2026-05-28T15:19:29+00:00

Replace the internal DRM framebuffer with a DRM client buffer. The client buffer allocates the DRM framebuffer on a file and also uses GEM object handles via the regular ADDFB2 interfaces. Using client-buffer interfaces unifies framebuffer allocation for DRM clients in user space and tegra's internal fbdev emulation. It also simplifies the clean-up side of the fbdev emulation. Signed-off-by: Thomas Zimmermann Signed-off-by: Thierry Reding Link: https://patch.msgid.link/20260421073646.144712-5-tzimmermann@suse.de

drm/tegra: fbdev: Calculate buffer geometry with format helpers

2026-05-28T15:19:29+00:00

Replace the geometry and size calculation in tegra's fbdev emulation with DRM format helpers. This consists of a 4CC lookup from the fbdev parameters, format lookup, pitch calculation and size calculation. Then allocate the GEM buffer object for the framebuffer memory from the calculated size. Set up mode_cmd with the calculated values just before allocating the framebuffer. This code will later be replaced with a DRM client buffer. Set framebuffer size fields in struct fb_info from the size stored in the GEM buffer object instead of what has been requested. The requested size is an estimate, while the buffer size is the exact value rounded to the correct alignment. Signed-off-by: Thomas Zimmermann Signed-off-by: Thierry Reding Link: https://patch.msgid.link/20260421073646.144712-4-tzimmermann@suse.de

drm/tegra: fbdev: Remove offset into framebuffer memory

2026-05-28T15:19:29+00:00

The screen_buffer field in struct fb_info contains the kernel address of the first byte of framebuffer memory. Do not add the display offset. This offset only describes scrolling during scanout. Signed-off-by: Thomas Zimmermann Fixes: de2ba664c30f ("gpu: host1x: drm: Add memory manager and fb") Cc: dri-devel@lists.freedesktop.org Cc: linux-tegra@vger.kernel.org Cc: # v3.10+ Signed-off-by: Thierry Reding Link: https://patch.msgid.link/20260421073646.144712-3-tzimmermann@suse.de

drm/tegra: fbdev: Do not assign to struct drm_fb_helper.info

2026-05-28T15:19:29+00:00

That field already contains the value being assigned. No need to do this twice. Signed-off-by: Thomas Zimmermann Fixes: 63c971af4036 ("drm/fb-helper: Allocate and release fb_info in single place") Cc: linux-tegra@vger.kernel.org Signed-off-by: Thierry Reding Link: https://patch.msgid.link/20260421073646.144712-2-tzimmermann@suse.de

drm/fb-helper: Allocate and release fb_info in single place

2025-11-25T10:02:43+00:00

Move the calls to drm_fb_helper_alloc_info() from drivers into a single place in fbdev helpers. Allocates struct fb_info for a new framebuffer device. Then call drm_fb_helper_single_fb_probe() to create an fbdev screen buffer. Also release the instance on errors by calling drm_fb_helper_release_info(). Simplifies the code and fixes the error cleanup for some of the drivers. Regular release of the struct fb_info instance still happens in drm_fb_helper_fini() as before. v2: - remove error rollback in driver implementations (kernel test robot) - initialize info in TTM implementation (kernel test robot) Signed-off-by: Thomas Zimmermann Acked-by: Christian König # radeon Acked-by: Dmitry Baryshkov # msm Acked-by: Javier Martinez Canillas Link: https://patch.msgid.link/20251027081245.80262-1-tzimmermann@suse.de

drm/client: Add client free callback to unprepare fb_helper

2025-10-24T06:44:10+00:00

Add free callback to struct drm_client_funcs. Invoke function to free the client memory as part of the release process. Implement free for fbdev emulation. Fbdev emulation allocates and prepares client memory in drm_fbdev_client_setup(). The release happens in fb_destroy from struct fb_ops. Multiple implementations of this callback exist in the various drivers that provide an fbdev implementation. Each of them needs to follow the implementation details of the fbdev setup code. Adding a free callback for the client puts the unprepare and release of the fbdev client in a single place. Signed-off-by: Thomas Zimmermann Reviewed-by: Dmitry Baryshkov # core, msm Acked-by: Tomi Valkeinen # omapdrm Acked-by: Patrik Jakobsson # gma500 Acked-by: Alex Deucher Link: https://lore.kernel.org/r/20251009132006.45834-2-tzimmermann@suse.de

drm/tegra: Pass along the format info from .fb_create() to drm_helper_mode_fill_fb_struct()

2025-07-16T17:11:34+00:00

Plumb the format info from .fb_create() all the way to drm_helper_mode_fill_fb_struct() to avoid the redundant lookup. For the fbdev case a manual drm_get_format_info() lookup is needed. Cc: Thierry Reding Cc: Mikko Perttunen Cc: linux-tegra@vger.kernel.org Reviewed-by: Thomas Zimmermann Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20250701090722.13645-17-ville.syrjala@linux.intel.com

drm/tegra: Run DRM default client setup

2024-09-26T07:31:29+00:00

Rework fbdev probing to support fbdev_probe in struct drm_driver and remove the old fb_probe callback. Provide an initializer macro for struct drm_driver that sets the callback according to the kernel configuration. Call drm_client_setup() to run the kernel's default client setup for DRM. Set fbdev_probe in struct drm_driver, so that the client setup can start the common fbdev client. The tegra driver specifies a preferred color mode of 32. As this is the default if no format has been given, leave it out entirely. v5: - select DRM_CLIENT_SELECTION Signed-off-by: Thomas Zimmermann Cc: Thierry Reding Cc: Mikko Perttunen Cc: Jonathan Hunter Acked-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20240924071734.98201-79-tzimmermann@suse.de

fbdev: Use _DMAMEM_ infix for DMA-memory helpers

2023-07-31T18:07:18+00:00

Change the infix for fbdev's DMA-memory helpers from _DMA_ to _DMAMEM_. The helpers perform operations within DMA-able memory, but they don't perform DMA operations. Naming should make this clear. Adapt all users. No functional changes. Signed-off-by: Thomas Zimmermann Reviewed-by: Sam Ravnborg Acked-by: Helge Deller Link: https://patchwork.freedesktop.org/patch/msgid/20230729193157.15446-4-tzimmermann@suse.de

drm/tegra: Store pointer to vmap'ed framebuffer in screen_buffer

2023-07-24T18:14:43+00:00

Tegra uses DMA-able memory, which has to be acessed with CPU ops for system-memory. Store the framebuffer's vmap address in struct fb_info.screen_buffer. The currently used field 'screen_base' is for I/O memory. Suggested-by: Thierry Reding Signed-off-by: Thomas Zimmermann Cc: Thierry Reding Cc: Mikko Perttunen Reviewed-by: Javier Martinez Canillas Acked-by: Thierry Reding Link: https://patchwork.freedesktop.org/patch/msgid/20230707083422.18691-6-tzimmermann@suse.de