Re: [PATCH v9 3/4] drm/xe: Use device wedged event

["Ghimiray, Himal Prasad" <himal.prasad.ghimiray@intel.com>]

On 15-11-2024 10:37, Raag Jadav wrote:
> This was previously attempted as xe specific reset uevent but dropped
> in commit 77a0d4d1cea2 ("drm/xe/uapi: Remove reset uevent for now")
> as part of refactoring.
> 
> Now that we have device wedged event provided by DRM core, make use
> of it and support both driver rebind and bus-reset based recovery.
> With this in place userspace will be notified of wedged device, on
> the basis of which, userspace may take respective action to recover
> the device.
> 
> $ udevadm monitor --property --kernel
> monitor will print the received events for:
> KERNEL - the kernel uevent
> 
> KERNEL[265.802982] change   /devices/pci0000:00/0000:00:01.0/0000:01:00.0/0000:02:01.0/0000:03:00.0/drm/card0 (drm)
> ACTION=change
> DEVPATH=/devices/pci0000:00/0000:00:01.0/0000:01:00.0/0000:02:01.0/0000:03:00.0/drm/card0
> SUBSYSTEM=drm
> WEDGED=rebind,bus-reset
> DEVNAME=/dev/dri/card0
> DEVTYPE=drm_minor
> SEQNUM=5208
> MAJOR=226
> MINOR=0


The patch in itself looks good. Do we have IGT tests in place to 
validate this uevent ?

BR
Himal

> 
> v2: Change authorship to Himal (Aravind)
>      Add uevent for all device wedged cases (Aravind)
> v3: Generic re-implementation in DRM subsystem (Lucas)
> v4: Change authorship to Raag (Aravind)
> 
> Signed-off-by: Raag Jadav <raag.jadav@intel.com>
> ---
>   drivers/gpu/drm/xe/xe_device.c | 9 +++++++--
>   1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> index 0e2dd691bdae..5878b331e35c 100644
> --- a/drivers/gpu/drm/xe/xe_device.c
> +++ b/drivers/gpu/drm/xe/xe_device.c
> @@ -989,11 +989,12 @@ static void xe_device_wedged_fini(struct drm_device *drm, void *arg)
>    * xe_device_declare_wedged - Declare device wedged
>    * @xe: xe device instance
>    *
> - * This is a final state that can only be cleared with a mudule
> + * This is a final state that can only be cleared with a module
>    * re-probe (unbind + bind).
>    * In this state every IOCTL will be blocked so the GT cannot be used.
>    * In general it will be called upon any critical error such as gt reset
> - * failure or guc loading failure.
> + * failure or guc loading failure. Userspace will be notified of this state
> + * by a DRM uevent.
>    * If xe.wedged module parameter is set to 2, this function will be called
>    * on every single execution timeout (a.k.a. GPU hang) right after devcoredump
>    * snapshot capture. In this mode, GT reset won't be attempted so the state of
> @@ -1023,6 +1024,10 @@ void xe_device_declare_wedged(struct xe_device *xe)
>   			"IOCTLs and executions are blocked. Only a rebind may clear the failure\n"
>   			"Please file a _new_ bug report at https://gitlab.freedesktop.org/drm/xe/kernel/issues/new\n",
>   			dev_name(xe->drm.dev));
> +
> +		/* Notify userspace of wedged device */
> +		drm_dev_wedged_event(&xe->drm,
> +				     DRM_WEDGE_RECOVERY_REBIND | DRM_WEDGE_RECOVERY_BUS_RESET);
>   	}
>   
>   	for_each_gt(gt, xe, id)