rtw88: pci: Power cycle device during shutdown

There are reports that 8822CE fails to work rtw88 with "failed to read DBI
register" error. Also I have a system with 8723DE which freezes the whole
system when the rtw88 is probing the device.

According to [1], platform firmware may not properly power manage the
device during shutdown. I did some expirements and putting the device to
D3 can workaround the issue.

So let's power cycle the device by putting the device to D3 at shutdown
to prevent the issue from happening.

[1] https://bugzilla.kernel.org/show_bug.cgi?id=206411#c9

BugLink: https://bugs.launchpad.net/bugs/1872984
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200928165508.20775-1-kai.heng.feng@canonical.com

diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c
index e72ea99..676d861 100644 (file)
--- a/drivers/net/wireless/realtek/rtw88/pci.c
+++ b/drivers/net/wireless/realtek/rtw88/pci.c
@@ -1601,6 +1601,8 @@ void rtw_pci_shutdown(struct pci_dev *pdev)
 
        if (chip->ops->shutdown)
                chip->ops->shutdown(rtwdev);
+
+       pci_set_power_state(pdev, PCI_D3hot);
 }
 EXPORT_SYMBOL(rtw_pci_shutdown);