Re: [PATCH v14 2/2] PCI: Add device-specific reset for Qualcomm WCN6855/WCN7850 WLAN

[sashiko-bot@kernel.org]

> Qualcomm WCN6855 (17cb:1103) and WCN7850 (17cb:1107) WLAN devices lack
> working reset methods for VFIO passthrough scenarios. These devices have no
> FLR capability, advertise NoSoftRst+ (blocking PM reset), and have broken
> bus reset (addressed by quirk_no_bus_reset, merged for v7.2).
> 
> VFIO attempts to reset devices on every reassignment. Without a working
> reset method, the attempt fails. On clean VM shutdown, the guest driver
> properly deinitializes the device via .shutdown/.remove callbacks, leaving
> it in a usable state despite the failed reset. However, on unclean VM
> termination (crash, force-off), the guest driver callbacks are not
> triggered, the device remains in an undefined state (DMA active, interrupts
> enabled, etc.), and without a working reset it cannot be reused.
> 
> Add a device-specific reset method using BAR-space hardware reset registers
> that exist in these devices.
> [ ... ]
> to previous approaches that failed after ~30 cycles. Device-specific reset
> is position #1 in the reset hierarchy, so these Qualcomm devices will use
> hardware reset as their primary reset method.
> 
> Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260917071651.14174-1-jtornosm@redhat.com?part=2