kernel/linux.git/drivers/gpu/drm/tiny, branch v6.19.11

drm/tiny: sharp-memory: fix pointer error dereference

2026-03-12T11:09:07+00:00

[ Upstream commit 46120745bb4e7e1f09959624716b4c5d6e2c2e9e ] The function devm_drm_dev_alloc() returns a pointer error upon failure not NULL. Change null check to pointer error check. Detected by Smatch: drivers/gpu/drm/tiny/sharp-memory.c:549 sharp_memory_probe() error: 'smd' dereferencing possible ERR_PTR() Fixes: b8f9f21716fec ("drm/tiny: Add driver for Sharp Memory LCD") Signed-off-by: Ethan Tidmore Reviewed-by: Thomas Zimmermann Signed-off-by: Thomas Zimmermann Link: https://patch.msgid.link/20260216040438.43702-1-ethantidmore06@gmail.com Signed-off-by: Sasha Levin

Merge tag 'v6.18-rc6' into drm-next

2025-11-20T22:55:08+00:00

Linux 6.18-rc6 Backmerge in order to merge msm next Signed-off-by: Dave Airlie

drm/tiny: pixpaper: add explicit dependency on MMU

2025-11-06T12:47:29+00:00

The DRM_GEM_SHMEM_HELPER helper requires MMU enabled because it uses vmf_insert_pfn() in its mmap implementation. On NOMMU configurations (e.g. some RISC-V randconfig builds), this symbol is unavailable and selecting DRM_GEM_SHMEM_HELPER causes a modpost undefined reference: ERROR: modpost: "vmf_insert_pfn" [drivers/gpu/drm/drm_shmem_helper.ko] undefined! Normally, Kconfig prevents this helper from being selected when CONFIG_MMU=n. However, in some randconfig builds (such as those used by 0day CI), select statements can override unmet dependencies, triggering the issue. Add an explicit dependency on MMU to DRM_PIXPAPER to prevent this. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202510280213.0rlYA4T3-lkp@intel.com/ Fixes: 0c4932f6ddf8 ("drm/tiny: pixpaper: Fix missing dependency on DRM_GEM_SHMEM_HELPER") Acked-by: Thomas Zimmermann Signed-off-by: LiangCheng Wang Signed-off-by: Thomas Zimmermann Link: https://patch.msgid.link/20251028-bar-v1-1-edfbd13fafff@gmail.com

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/cirrus-qemu: Use vblank timer

2025-10-15T08:29:49+00:00

Use a vblank timer to simulate the vblank interrupt. The DRM vblank helpers provide an implementation on top of Linux' hrtimer. Cirrus-qemu enables and disables the timer as part of the CRTC. The atomic_flush callback sets up the event. Like vblank interrupts, the vblank timer fires at the rate of the display refresh. Most userspace limits its page flip rate according to the DRM vblank event. Cirrus-qemu' virtual hardware does not provide vblank interrupts, so DRM sends each event ASAP. With the fast access times of virtual display memory, the event rate is much higher than the display mode's refresh rate; creating the next page flip almost immediately. This leads to excessive CPU overhead from even small display updates, such as moving the mouse pointer. This problem affects cirrus-qemu and all other virtual displays. See [1] for a discussion in the context of hypervdrm. Signed-off-by: Thomas Zimmermann Link: https://lore.kernel.org/dri-devel/SN6PR02MB415702B00D6D52B0EE962C98D46CA@SN6PR02MB4157.namprd02.prod.outlook.com/ # [1] Acked-by: Gerd Hoffmann Link: https://lore.kernel.org/r/20251008121450.227997-1-tzimmermann@suse.de

drm/bochs: Use vblank timer

2025-10-15T08:29:39+00:00

Use a vblank timer to simulate the vblank interrupt. The DRM vblank helpers provide an implementation on top of Linux' hrtimer. Bochs enables and disables the timer as part of the CRTC. The atomic_flush callback sets up the event. Like vblank interrupts, the vblank timer fires at the rate of the display refresh. Most userspace limits its page flip rate according to the DRM vblank event. Bochs' virtual hardware does not provide vblank interrupts, so DRM sends each event ASAP. With the fast access time of virtual display memory, the event rate is much higher than the display mode's refresh rate; creating the next page flip almost immediately. This leads to excessive CPU overhead from even small display updates, such as moving the mouse pointer. This problem affects bochs and all other virtual displays. See [1] for a discussion in the context of hypervdrm. Signed-off-by: Thomas Zimmermann Link: https://lore.kernel.org/dri-devel/SN6PR02MB415702B00D6D52B0EE962C98D46CA@SN6PR02MB4157.namprd02.prod.outlook.com/ # [1] Acked-by: Gerd Hoffmann Link: https://lore.kernel.org/r/20251008093931.19138-1-tzimmermann@suse.de

drm/tiny: pixpaper: Fix missing dependency on DRM_GEM_SHMEM_HELPER

2025-09-23T12:07:04+00:00

The driver uses drm_gem_shmem_prime_import_no_map() and drm_gem_shmem_dumb_create(), but the Kconfig currently selects DRM_GEM_DMA_HELPER instead of DRM_GEM_SHMEM_HELPER. This causes link failures when DRM_GEM_SHMEM_HELPER is not enabled. Select DRM_GEM_SHMEM_HELPER to fix the build. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202509220320.gfFZjmyg-lkp@intel.com/ Fixes: c9e70639f591 ("drm: tiny: Add support for Mayqueen Pixpaper e-ink panel") Reviewed-by: Thomas Zimmermann Signed-off-by: LiangCheng Wang Signed-off-by: Thomas Zimmermann Link: https://lore.kernel.org/r/20250922-bar-v1-1-b2a1f54ace82@gmail.com

drm/pixpaper: Fix return type of pixpaper_mode_valid()

2025-09-15T10:29:37+00:00

When building with -Wincompatible-function-pointer-types-strict, a warning designed to catch kernel control flow integrity (kCFI) issues at build time, there is an instance in the new tiny DRM pixpaper driver: drivers/gpu/drm/tiny/pixpaper.c:982:16: error: incompatible function pointer types initializing 'enum drm_mode_status (*)(struct drm_crtc *, const struct drm_display_mode *)' with an expression of type 'int (struct drm_crtc *, const struct drm_display_mode *)' [-Werror,-Wincompatible-function-pointer-types-strict] 982 | .mode_valid = pixpaper_mode_valid, | ^~~~~~~~~~~~~~~~~~~ While 'int' and 'enum drm_mode_status' are ABI compatible, hence no regular warning from -Wincompatible-function-pointer-types, the mismatch will trigger a kCFI violation when pixpaper_mode_valid() is called indirectly. Update the return type of pixpaper_mode_valid() to be 'enum drm_mode_status' to clear up the warning and kCFI violation. Fixes: c9e70639f591 ("drm: tiny: Add support for Mayqueen Pixpaper e-ink panel") Signed-off-by: Nathan Chancellor Reviewed-by: Thomas Zimmermann Signed-off-by: Thomas Zimmermann Link: https://lore.kernel.org/r/20250908-drm-pixpaper-fix-mode_valid-return-type-v1-1-705ceaf03757@kernel.org

drm/tiny/bochs: Convert dev_err() to drm_err()

2025-09-08T12:50:35+00:00

The DRM subsystem has a set of preferred, prefixed logging functions (drm_info, drm_warn, drm_err) which improve debuggability by including the driver and function name in the log output. As part of the ongoing effort to modernize logging calls, convert a dev_err() call in the bochs hardware initialization function to its drm_err() equivalent. This work was suggested by the DRM TODO list. Signed-off-by: Leander Kieweg Reviewed-by: Thomas Zimmermann Signed-off-by: Thomas Zimmermann Link: https://lore.kernel.org/r/20250818113530.187440-1-kieweg.leander@gmail.com

drm: tiny: Add support for Mayqueen Pixpaper e-ink panel

2025-09-05T12:53:07+00:00

Introduce a DRM driver for the Mayqueen Pixpaper e-ink display panel, which is controlled via SPI. The driver supports a 122x250 resolution display with XRGB8888 format. Also, add a MAINTAINERS entry for the Pixpaper driver. Signed-off-by: LiangCheng Wang Reviewed-by: Thomas Zimmermann Signed-off-by: Thomas Zimmermann Link: https://lore.kernel.org/r/20250902-drm-v5-3-d77c678c4ae3@gmail.com