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rtw88: Disable PCIe ASPM while doing NAPI poll on 8821CE
authorKai-Heng Feng <kai.heng.feng@canonical.com>
Wed, 15 Dec 2021 11:46:34 +0000 (19:46 +0800)
committerKalle Valo <kvalo@kernel.org>
Mon, 20 Dec 2021 18:48:10 +0000 (20:48 +0200)
commit24f5e38a13b5ae2b6105cda8bb47c19108e62a9a
treee05316b6b76c3b27475824b0ba98547b6202c7c5
parent4894edacfa93d7046bec4fc61fc402ac6a2ac9e8
rtw88: Disable PCIe ASPM while doing NAPI poll on 8821CE

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@canonical.com>
Acked-by: Jian-Hong Pan <jhp@endlessos.org>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20211215114635.333767-1-kai.heng.feng@canonical.com
drivers/net/wireless/realtek/rtw88/pci.c
drivers/net/wireless/realtek/rtw88/pci.h