RE: [PATCH] wifi: rtw89: 8852be: add .shutdown callback to quiesce device on reboot

[Ping-Ke Shih <pkshih@realtek.com>]

yhchen312@gmail.com <yhchen312@gmail.com> wrote:
> Hi Ping-Ke,
> 
> Thanks for the review.
> 
> > Does it mean the work is running after .shutdown but before .remove?
> 
> On the reboot/poweroff path the kernel only runs device_shutdown(),
> which invokes each driver's .shutdown callback; .remove is *not* called
> on this path -- it only runs on driver unbind, module unload or
> hot-unplug.  The rfkill polling workqueue, however, keeps being scheduled
> by the rfkill core throughout the whole shutdown sequence until the
> system finally halts.  During that window the platform starts tearing
> the PCIe link down, and the next MMIO read issued by
> rtw89_ops_rfkill_poll() then targets a non-responding device, which on
> arm64 is reported as a fatal asynchronous SError.  So it is not ".remove
> after .shutdown"; .remove never runs on reboot -- the poll work simply
> outlives the link, and that is exactly what the new flag stops.

Thanks for the detail. 

Ping-Ke