kernel/linux.git/include/drm/drm_drv.h, branch v6.18.22

drm: move drm based debugfs funcs to drm_debugfs.c

2025-07-04T13:58:22+00:00

Requirement is to create per client-id based directories to hold key debugging information and for that access to root debugfs dentry is need which is not in one place and that information cannot be stored in drm_device. Move the debugfs functionality from drm_drv.c and drm_accel.c to drm_debugfs.c This enables debugfs root node reference directly drm_debugfs.c and hence enable to create per client-id directory. v8: Create drm_accel dentry only if it's config is enabled (Jeff, Hugo) v8: Merge drm_drv and drm_accel debugfs patches (Koenig, Christian) v10: Since we moved drm_debugfs_root, hence to handle drm bridge debugfs add a new function which call drm_bridge_debugfs_params where drm_debugfs_root is accessible. Suggested-by: Christian König Signed-off-by: Sunil Khatri Link: https://lore.kernel.org/r/20250704075548.1549849-2-sunil.khatri@amd.com Reviewed-by: Christian König Signed-off-by: Christian König

drm: Create a task info option for wedge events

2025-06-17T14:32:47+00:00

When a device get wedged, it might be caused by a guilty application. For userspace, knowing which task was involved can be useful for some situations, like for implementing a policy, logs or for giving a chance for the compositor to let the user know what task was involved in the problem. This is an optional argument, when the task info is not available, the PID and TASK string won't appear in the event string. Sometimes just the PID isn't enough giving that the task might be already dead by the time userspace will try to check what was this PID's name, so to make the life easier also notify what's the task's name in the user event. Acked-by: Rodrigo Vivi Reviewed-by: Krzysztof Karas Reviewed-by: Raag Jadav Acked-by: Christian König Link: https://lore.kernel.org/r/20250617124949.2151549-4-andrealmeid@igalia.com Signed-off-by: André Almeida

drm: drv: implement __drm_dev_alloc()

2025-04-24T11:50:03+00:00

In the Rust DRM device abstraction we need to allocate a struct drm_device. Currently, there are two options, the deprecated drm_dev_alloc() (which does not support subclassing) and devm_drm_dev_alloc(). The latter supports subclassing, but also manages the initial reference through devres for the parent device. In Rust we want to conform with the subclassing pattern, but do not want to get the initial reference managed for us, since Rust has its own, idiomatic ways to properly deal with it. There are two options to achieve this. 1) Allocate the memory ourselves with a KBox. 2) Implement __drm_dev_alloc(), which supports subclassing, but is unmanged. While (1) would be possible, it would be cumbersome, since it would require exporting drm_dev_init() and drmm_add_final_kfree(). Hence, go with option (2) and implement __drm_dev_alloc(). Reviewed-by: Maxime Ripard Reviewed-by: Alyssa Rosenzweig Reviewed-by: Lyude Paul Link: https://lore.kernel.org/r/20250410235546.43736-2-dakr@kernel.org Signed-off-by: Danilo Krummrich

drm: Introduce device wedged event

2025-02-13T17:15:43+00:00

Introduce device wedged event, which notifies userspace of 'wedged' (hanged/unusable) state of the DRM device through a uevent. This is useful especially in cases where the device is no longer operating as expected and has become unrecoverable from driver context. Purpose of this implementation is to provide drivers a generic way to recover the device with the help of userspace intervention without taking any drastic measures (like resetting or re-enumerating the full bus, on which the underlying physical device is sitting) in the driver. A 'wedged' device is basically a device that is declared dead by the driver after exhausting all possible attempts to recover it from driver context. The uevent is the notification that is sent to userspace along with a hint about what could possibly be attempted to recover the device from userspace and bring it back to usable state. Different drivers may have different ideas of a 'wedged' device depending on hardware implementation of the underlying physical device, and hence the vendor agnostic nature of the event. It is up to the drivers to decide when they see the need for device recovery and how they want to recover from the available methods. Driver prerequisites -------------------- The driver, before opting for recovery, needs to make sure that the 'wedged' device doesn't harm the system as a whole by taking care of the prerequisites. Necessary actions must include disabling DMA to system memory as well as any communication channels with other devices. Further, the driver must ensure that all dma_fences are signalled and any device state that the core kernel might depend on is cleaned up. All existing mmaps should be invalidated and page faults should be redirected to a dummy page. Once the event is sent, the device must be kept in 'wedged' state until the recovery is performed. New accesses to the device (IOCTLs) should be rejected, preferably with an error code that resembles the type of failure the device has encountered. This will signify the reason for wedging, which can be reported to the application if needed. Recovery -------- Current implementation defines three recovery methods, out of which, drivers can use any one, multiple or none. Method(s) of choice will be sent in the uevent environment as ``WEDGED=[,..,]`` in order of less to more side-effects. If driver is unsure about recovery or method is unknown (like soft/hard system reboot, firmware flashing, physical device replacement or any other procedure which can't be attempted on the fly), ``WEDGED=unknown`` will be sent instead. Userspace consumers can parse this event and attempt recovery as per the following expectations. =============== ======================================== Recovery method Consumer expectations =============== ======================================== none optional telemetry collection rebind unbind + bind driver bus-reset unbind + bus reset/re-enumeration + bind unknown consumer policy =============== ======================================== The only exception to this is ``WEDGED=none``, which signifies that the device was temporarily 'wedged' at some point but was recovered from driver context using device specific methods like reset. No explicit recovery is expected from the consumer in this case, but it can still take additional steps like gathering telemetry information (devcoredump, syslog). This is useful because the first hang is usually the most critical one which can result in consequential hangs or complete wedging. Consumer prerequisites ---------------------- It is the responsibility of the consumer to make sure that the device or its resources are not in use by any process before attempting recovery. With IOCTLs erroring out, all device memory should be unmapped and file descriptors should be closed to prevent leaks or undefined behaviour. The idea here is to clear the device of all user context beforehand and set the stage for a clean recovery. Example ------- Udev rule:: SUBSYSTEM=="drm", ENV{WEDGED}=="rebind", DEVPATH=="*/drm/card[0-9]", RUN+="/path/to/rebind.sh $env{DEVPATH}" Recovery script:: #!/bin/sh DEVPATH=$(readlink -f /sys/$1/device) DEVICE=$(basename $DEVPATH) DRIVER=$(readlink -f $DEVPATH/driver) echo -n $DEVICE > $DRIVER/unbind echo -n $DEVICE > $DRIVER/bind Customization ------------- Although basic recovery is possible with a simple script, consumers can define custom policies around recovery. For example, if the driver supports multiple recovery methods, consumers can opt for the suitable one depending on scenarios like repeat offences or vendor specific failures. Consumers can also choose to have the device available for debugging or telemetry collection and base their recovery decision on the findings. This is useful especially when the driver is unsure about recovery or method is unknown. v4: s/drm_dev_wedged/drm_dev_wedged_event Use drm_info() (Jani) Kernel doc adjustment (Aravind) v5: Send recovery method with uevent (Lina) v6: Access wedge_recovery_opts[] using helper function (Jani) Use snprintf() (Jani) v7: Convert recovery helpers into regular functions (Andy, Jani) Aesthetic adjustments (Andy) Handle invalid recovery method v8: Allow sending multiple methods with uevent (Lucas, Michal) static_assert() globally (Andy) v9: Provide 'none' method for device reset (Christian) Provide recovery opts using switch cases v11: Log device reset (André) Signed-off-by: Raag Jadav Reviewed-by: André Almeida Reviewed-by: Christian König Link: https://patchwork.freedesktop.org/patch/msgid/20250204070528.1919158-2-raag.jadav@intel.com Signed-off-by: Rodrigo Vivi

Merge tag 'cgroup-dmem-drm-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/mripard/linux into drm-next

2025-01-10T21:20:29+00:00

DMEM cgroup pull request This introduces a new cgroup controller to limit the device memory. Notable users would be DRM, dma-buf heaps, or v4l2. This pull request is based on the series developped by Maarten Lankhorst, Friedrich Vock, and I: https://lore.kernel.org/all/20241204134410.1161769-1-dev@lankhorst.se/ Signed-off-by: Dave Airlie From: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20250110-cryptic-warm-mandrill-b71f5d@houat

drm/drv: Add drmm managed registration helper for dmem cgroups.

2025-01-06T16:25:35+00:00

Drivers will need to register dmem regions at probe time, so let's give them a drm-managed helper. Signed-off-by: Maarten Lankhorst Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20241204134410.1161769-3-dev@lankhorst.se Signed-off-by: Maxime Ripard

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

drm: Fix for kernel doc warning

2024-10-09T15:31:38+00:00

Added colon in kernel-doc comment to fix the warning. ./include/drm/drm_drv.h:372: warning: Incorrect use of kernel-doc format: * @fbdev_probe ./include/drm/drm_drv.h:435: warning: Function parameter or struct member 'fbdev_probe' not described in 'drm_driver' Signed-off-by: R Sundar Link: https://patchwork.freedesktop.org/patch/msgid/20241003023806.17537-1-prosunofficial@gmail.com Signed-off-by: Jani Nikula

drm/fbdev: Add memory-agnostic fbdev client

2024-09-26T06:27:50+00:00

Add an fbdev client that can work with any memory manager. The client implementation is the same as existing code in fbdev-dma or fbdev-shmem. Provide struct drm_driver.fbdev_probe for the new client to allocate the surface GEM buffer. The new callback replaces fb_probe of struct drm_fb_helper_funcs, which does the same. To use the new client, DRM drivers set fbdev_probe in their struct drm_driver instance and call drm_fbdev_client_setup(). Probing and creating the fbdev surface buffer is now independent from the other operations in struct drm_fb_helper. For the pixel format, the fbdev client either uses a specified format, the value in preferred_depth or 32-bit RGB. v2: - test for struct drm_fb_helper.funcs for NULL (Sui) - respect struct drm_mode_config.preferred_depth for default format Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20240924071734.98201-4-tzimmermann@suse.de

drm: Remove struct drm_driver.lastclose

2024-08-13T14:21:12+00:00

The lastclose callback in struct drm_driver is unused. Remove it. Also update documentation. v2: - update to use drm_lastclose() - fix typo in documentation Signed-off-by: Thomas Zimmermann Reviewed-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20240812083000.337744-9-tzimmermann@suse.de