Re: [PATCH 2/13] drm/xe: Separate AER reset state from device wedging

[Raag Jadav <raag.jadav@intel.com>]

Cc: Riana

On Thu, Aug 27, 2026 at 03:47:50PM +0530, Arvind Yadav wrote:
> PCI error recovery currently uses xe->wedged.flag to block driver
> access. This mixes a temporary AER reset with a permanent device wedge.
> 
> If the device wedges during AER recovery, the wedge is not seen as the
> first transition. The AER resume callback may then clear the flag and
> make the permanently wedged device appear usable again.
> 
> Keep the old device blocked while slot reset removes it, and block the
> new device until the AER resume callback.
> 
> The old AER path took a runtime PM reference to balance
> xe_device_wedged_fini(), which drops one when wedged.flag is set. AER no
> longer sets that flag, so keeping the Xe-owned reference would leak it.
> pcie_do_recovery() holds a PCI-core runtime PM reference across the
> error_detected, slot_reset and resume callbacks.

...

> +/*
> + * Return true when device access must be blocked either permanently because
> + * the device is wedged or temporarily while PCI error recovery is running.
> + *
> + * Do not use this helper for one-way wedged-device decisions such as DMA
> + * isolation, IRQ resume suppression or recovery-method reporting.
> + */
> +static inline bool xe_device_io_blocked(struct xe_device *xe)
> +{
> +	return xe_device_wedged(xe) || xe_device_is_in_reset(xe);
> +}

This is already documented below but still FYI:

The long term plan to reuse FLR flow[1] in AER path and move over from
'reset' states to temporary wedging.

Raag

[1] https://patchwork.freedesktop.org/series/162055/

> @@ -116,7 +116,6 @@ static pci_ers_result_t xe_pci_error_slot_reset(struct pci_dev *pdev)
>  	 * TODO: optimize by re-initializing only the hardware state and re-creating
>  	 * kernel BOs.
>  	 */
> -	xe_device_clear_in_reset(xe);
>  	pdev->driver->remove(pdev);
>  	devres_release_group(&pdev->dev, xe->devres_group);