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)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 27 Jan 2022 10:03:42 +0000 (11:03 +0100)
commit617339466fda09916c4b4151fa5e6a9c1fdae353
tree1ad161c301e17f32b854e5bbc83018de26094028
parent9b6b5f07702fa0970cdd767e85afc671b0d82c7d
rtw88: Disable PCIe ASPM while doing NAPI poll on 8821CE

[ Upstream commit 24f5e38a13b5ae2b6105cda8bb47c19108e62a9a ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/net/wireless/realtek/rtw88/pci.c
drivers/net/wireless/realtek/rtw88/pci.h