Re: [PATCH v5 3/4] drm/xe: Use device wedged event

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

On 17-09-2024 09:32, 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 supported by DRM core, make use
> of it. 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.


As per earlier discussions, the UAPI was also supposed to provide the 
reason for wedging( which is supposedly used by L0). IS that requirement 
nomore in place ?

BR
Himal


> 
> $ 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=bus-reset
> DEVNAME=/dev/dri/card0
> DEVTYPE=drm_minor
> SEQNUM=5208
> MAJOR=226
> MINOR=0
> 
> 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 | 17 +++++++++++++++--
>   drivers/gpu/drm/xe/xe_device.h |  1 +
>   drivers/gpu/drm/xe/xe_pci.c    |  2 ++
>   3 files changed, 18 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> index 4d3c794f134c..1b097643aacb 100644
> --- a/drivers/gpu/drm/xe/xe_device.c
> +++ b/drivers/gpu/drm/xe/xe_device.c
> @@ -780,6 +780,15 @@ int xe_device_probe(struct xe_device *xe)
>   	return err;
>   }
>   
> +void xe_setup_wedge_recovery(struct xe_device *xe)
> +{
> +	struct drm_device *dev = &xe->drm;
> +
> +	/* Support both driver rebind and bus reset based recovery. */
> +	set_bit(DRM_WEDGE_RECOVERY_REBIND, &dev->wedge_recovery);
> +	set_bit(DRM_WEDGE_RECOVERY_BUS_RESET, &dev->wedge_recovery);
> +}
> +
>   static void xe_device_remove_display(struct xe_device *xe)
>   {
>   	xe_display_unregister(xe);
> @@ -986,11 +995,12 @@ 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
> @@ -1020,6 +1030,9 @@ 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_BUS_RESET);
>   	}
>   
>   	for_each_gt(gt, xe, id)
> diff --git a/drivers/gpu/drm/xe/xe_device.h b/drivers/gpu/drm/xe/xe_device.h
> index ca8d8ef6342b..77a2332b4b87 100644
> --- a/drivers/gpu/drm/xe/xe_device.h
> +++ b/drivers/gpu/drm/xe/xe_device.h
> @@ -174,6 +174,7 @@ static inline bool xe_device_wedged(struct xe_device *xe)
>   	return atomic_read(&xe->wedged.flag);
>   }
>   
> +void xe_setup_wedge_recovery(struct xe_device *xe);
>   void xe_device_declare_wedged(struct xe_device *xe);
>   
>   struct xe_file *xe_file_get(struct xe_file *xef);
> diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
> index a1d08e20cd34..60a8a60f1d9f 100644
> --- a/drivers/gpu/drm/xe/xe_pci.c
> +++ b/drivers/gpu/drm/xe/xe_pci.c
> @@ -872,6 +872,8 @@ static int xe_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>   	if (err)
>   		goto err_driver_cleanup;
>   
> +	xe_setup_wedge_recovery(xe);
> +
>   	drm_dbg(&xe->drm, "d3cold: capable=%s\n",
>   		str_yes_no(xe->d3cold.capable));
>