Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> wrote:
> Many Intel based platforms face system random freeze after commit
> 9e2fd29864c5 ("rtw88: add napi support").
>
> The commit itself shouldn't be the culprit. My guess is that the 8821CE
> only leaves ASPM L1 for a short period when IRQ is raised. Since IRQ is
> masked during NAPI polling, the PCIe link stays at L1 and makes RX DMA
> extremely slow. Eventually the RX ring becomes messed up:
> [ 1133.194697] rtw_8821ce 0000:02:00.0: pci bus timeout, check dma status
>
> Since the 8821CE hardware may fail to leave ASPM L1, manually do it in
> the driver to resolve the issue.
>
> Fixes: 9e2fd29864c5 ("rtw88: add napi support")
> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215131
> BugLink: https://bugs.launchpad.net/bugs/1927808
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
> Acked-by: Jian-Hong Pan <jhp@xxxxxxxxxxxxx>
Patch applied to wireless-drivers-next.git, thanks.
24f5e38a13b5 rtw88: Disable PCIe ASPM while doing NAPI poll on 8821CE
--
https://patchwork.kernel.org/project/linux-wireless/patch/20211215114635.333767-1-kai.heng.feng@xxxxxxxxxxxxx/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
