kernel/linux.git/drivers/gpu/drm/tiny/bochs.c, branch v7.1-rc5

drm/bochs: Drop manual put on probe error path

2026-05-07T08:51:18+00:00

bochs_pci_probe() allocates the DRM device with devm_drm_dev_alloc(), which registers a devres action to drop the initial DRM device reference on driver detach or probe failure. The error path currently calls drm_dev_put() manually. If probe then returns an error, devres will run the registered release action and put the same device again, after the first put may already have released it. Return the probe error directly and let devres own the final put. Signed-off-by: Myeonghun Pak Fixes: 04826f588682 ("drm/bochs: Allocate DRM device in struct bochs_device") Signed-off-by: Thomas Zimmermann Reviewed-by: Thomas Zimmermann Link: https://patch.msgid.link/20260424123506.32275-1-mhun512@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/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/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/bochs: Add support for drm_panic

2025-06-23T09:30:18+00:00

Add drm_panic module for bochs drm so that panic screen can be displayed on panic. Signed-off-by: Ryosuke Yasuoka Reviewed-by: Jocelyn Falempe Link: https://lore.kernel.org/r/20250613132023.106946-1-ryasuoka@redhat.com Signed-off-by: Jocelyn Falempe

drm/bochs: Fix DPMS regression

2025-03-06T07:54:42+00:00

The recent rewrite with the use of regular atomic helpers broke the DPMS unblanking on X11. Fix it by moving the call of bochs_hw_blank(false) from CRTC mode_set_nofb() to atomic_enable(). Fixes: 2037174993c8 ("drm/bochs: Use regular atomic helpers") Link: https://bugzilla.suse.com/show_bug.cgi?id=1238209 Signed-off-by: Takashi Iwai Reviewed-by: Thomas Zimmermann Signed-off-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20250304134203.20534-1-tiwai@suse.de

Merge remote-tracking branch 'drm-misc/drm-misc-next-fixes' into drm-misc-fixes

2025-02-06T08:59:35+00:00

Merge the few remaining patches stuck into drm-misc-next-fixes. Signed-off-by: Maxime Ripard

drm/bochs: Do not put DRM device in PCI remove callback

2025-01-23T06:37:29+00:00

Removing the bochs PCI device should mark the DRM device as unplugged without removing it. Hence clear the respective call to drm_dev_put() from bochs_pci_remove(). Fixes a double unref in devm_drm_dev_init_release(). An example error message is shown below: [ 32.958338] BUG: KASAN: use-after-free in drm_dev_put.part.0+0x1b/0x90 [ 32.958850] Write of size 4 at addr ffff888152134004 by task (udev-worker)/591 [ 32.959574] CPU: 3 UID: 0 PID: 591 Comm: (udev-worker) Tainted: G E 6.13.0-rc2-1-default+ #3417 [ 32.960316] Tainted: [E]=UNSIGNED_MODULE [ 32.960637] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-2-gc13ff2cd-prebuilt.qemu.org 04/01/2014 [ 32.961429] Call Trace: [ 32.961433] [ 32.961439] dump_stack_lvl+0x68/0x90 [ 32.961452] print_address_description.constprop.0+0x88/0x330 [ 32.961461] ? preempt_count_sub+0x14/0xc0 [ 32.961473] print_report+0xe2/0x1d0 [ 32.961479] ? srso_alias_return_thunk+0x5/0xfbef5 [ 32.963725] ? __virt_addr_valid+0x143/0x320 [ 32.964077] ? srso_alias_return_thunk+0x5/0xfbef5 [ 32.964463] ? drm_dev_put.part.0+0x1b/0x90 [ 32.964817] kasan_report+0xce/0x1a0 [ 32.965123] ? drm_dev_put.part.0+0x1b/0x90 [ 32.965474] kasan_check_range+0xff/0x1c0 [ 32.965806] drm_dev_put.part.0+0x1b/0x90 [ 32.966138] release_nodes+0x84/0xc0 [ 32.966447] devres_release_all+0xd2/0x110 [ 32.966788] ? __pfx_devres_release_all+0x10/0x10 [ 32.967177] ? preempt_count_sub+0x14/0xc0 [ 32.967523] device_unbind_cleanup+0x16/0xc0 [ 32.967886] really_probe+0x1b7/0x570 [ 32.968207] __driver_probe_device+0xca/0x1b0 [ 32.968568] driver_probe_device+0x4a/0xf0 [ 32.968907] __driver_attach+0x10b/0x290 [ 32.969239] ? __pfx___driver_attach+0x10/0x10 [ 32.969598] bus_for_each_dev+0xc0/0x110 [ 32.969923] ? __pfx_bus_for_each_dev+0x10/0x10 [ 32.970291] ? bus_add_driver+0x17a/0x2b0 [ 32.970622] ? srso_alias_return_thunk+0x5/0xfbef5 [ 32.971011] bus_add_driver+0x19a/0x2b0 [ 32.971335] driver_register+0xd8/0x160 [ 32.971671] ? __pfx_bochs_pci_driver_init+0x10/0x10 [bochs] [ 32.972130] do_one_initcall+0xba/0x390 [...] After unplugging the DRM device, clients will close their references. Closing the final reference will also release the DRM device. Reported-by: Dr. David Alan Gilbert Closes: https://lore.kernel.org/lkml/Z18dbfDAiFadsSdg@gallifrey/ Fixes: 04826f588682 ("drm/bochs: Allocate DRM device in struct bochs_device") Cc: Thomas Zimmermann Cc: Gerd Hoffmann Cc: virtualization@lists.linux.dev Signed-off-by: Thomas Zimmermann Reviewed-by: Dmitry Baryshkov Link: https://patchwork.freedesktop.org/patch/msgid/20250103095615.231162-1-tzimmermann@suse.de

drm: remove driver date from struct drm_driver and all drivers

2024-12-05T10:35:42+00:00

We stopped using the driver initialized date in commit 7fb8af6798e8 ("drm: deprecate driver date") and (eventually) started returning "0" for drm_version ioctl instead. Finish the job, and remove the unused date member from struct drm_driver, its initialization from drivers, along with the common DRIVER_DATE macros. v2: Also update drivers/accel (kernel test robot) Reviewed-by: Javier Martinez Canillas Acked-by: Alex Deucher Acked-by: Simon Ser Acked-by: Jeffrey Hugo Acked-by: Lucas De Marchi Acked-by: Dmitry Baryshkov # msm Reviewed-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/1f2bf2543aed270a06f6c707fd6ed1b78bf16712.1733322525.git.jani.nikula@intel.com Signed-off-by: Jani Nikula

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

2024-12-02T11:44:18+00:00

Kickstart 6.14 cycle. Signed-off-by: Maxime Ripard