[PATCH v3 1/7] drm: Add a vendor-specific recovery method to device wedged uevent

[Raag Jadav]

On Wed, Jul 02, 2025 at 07:41:11PM +0530, Riana Tauro wrote:
> Certain errors can cause the device to be wedged and may
> require a vendor specific recovery method to restore normal
> operation.
> 
> Add a recovery method 'WEDGED=vendor-specific' for such errors. Vendors
> must provide additional recovery documentation if this method
> is used.
> 
> Cc: André Almeida <andrealmeid at igalia.com>
> Cc: Christian König <christian.koenig at amd.com>
> Cc: David Airlie <airlied at gmail.com>
> Cc: <dri-devel at lists.freedesktop.org>
> Suggested-by: Raag Jadav <raag.jadav at intel.com>
> Signed-off-by: Riana Tauro <riana.tauro at intel.com>
> ---
>  Documentation/gpu/drm-uapi.rst | 5 ++++-
>  drivers/gpu/drm/drm_drv.c      | 2 ++
>  include/drm/drm_device.h       | 4 ++++
>  3 files changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/gpu/drm-uapi.rst b/Documentation/gpu/drm-uapi.rst
> index 263e5a97c080..1ea835a3fc66 100644
> --- a/Documentation/gpu/drm-uapi.rst
> +++ b/Documentation/gpu/drm-uapi.rst
> @@ -424,7 +424,9 @@ uevent environment as ``WEDGED=<method1>[,..,<methodN>]`` 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``

We may also want to remove the examples for unknown method so that we
don't confuse users in case any of it overlaps with vendor-specific.

> -will be sent instead.
> +will be sent instead. If recovery method is specific to vendor
> +``WEDGED=vendor-specific`` will be sent and userspace should refer to vendor
> +specific documentation for further recovery steps.
>  
>  Userspace consumers can parse this event and attempt recovery as per the
>  following expectations.
> @@ -435,6 +437,7 @@ following expectations.
>      none            optional telemetry collection
>      rebind          unbind + bind driver
>      bus-reset       unbind + bus reset/re-enumeration + bind
> +    vendor-specific vendor specific recovery method
>      unknown         consumer policy
>      =============== ========================================
>  
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index 02556363e918..c72e5c67479d 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -535,6 +535,8 @@ static const char *drm_get_wedge_recovery(unsigned int opt)
>  		return "rebind";
>  	case DRM_WEDGE_RECOVERY_BUS_RESET:
>  		return "bus-reset";
> +	case DRM_WEDGE_RECOVERY_VENDOR:
> +		return "vendor-specific";
>  	default:
>  		return NULL;
>  	}
> diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h
> index 08b3b2467c4c..40a4caaa6313 100644
> --- a/include/drm/drm_device.h
> +++ b/include/drm/drm_device.h
> @@ -26,10 +26,14 @@ struct pci_controller;
>   * Recovery methods for wedged device in order of less to more side-effects.
>   * To be used with drm_dev_wedged_event() as recovery @method. Callers can
>   * use any one, multiple (or'd) or none depending on their needs.
> + *
> + * If DRM_WEDGE_RECOVERY_VENDOR method is used, vendors must provide additional
> + * documentation outlining further recovery steps.

The original documentation is sufficient so let's not duplicate specific
cases here.

Raag

>   */
>  #define DRM_WEDGE_RECOVERY_NONE		BIT(0)	/* optional telemetry collection */
>  #define DRM_WEDGE_RECOVERY_REBIND	BIT(1)	/* unbind + bind driver */
>  #define DRM_WEDGE_RECOVERY_BUS_RESET	BIT(2)	/* unbind + reset bus device + bind */
> +#define DRM_WEDGE_RECOVERY_VENDOR	BIT(3)	/* vendor specific recovery method */
>  
>  /**
>   * struct drm_wedge_task_info - information about the guilty task of a wedge dev
> -- 
> 2.47.1
>