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

[Riana Tauro <riana.tauro@intel.com>]

On 7/3/2025 9:36 AM, Raag Jadav wrote:
> 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@igalia.com>
>> Cc: Christian König <christian.koenig@amd.com>
>> Cc: David Airlie <airlied@gmail.com>
>> Cc: <dri-devel@lists.freedesktop.org>
>> Suggested-by: Raag Jadav <raag.jadav@intel.com>
>> Signed-off-by: Riana Tauro <riana.tauro@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.

Okay will remove this

> 
>> -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.

Added it here so anyone checking the code directly is aware.

Riana>
> 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
>>