2021-12-13 08:11:40

by Jian-Hong Pan

Subject: [PATCH] rtw88: pci: turn off PCI ASPM during NAPI polling

The system on the machines equipped with RTL8821CE freezes randomly
until the PCI ASPM is disabled during NAPI poll function.

Link: https://www.spinics.net/lists/linux-wireless/msg218387.html
Fixes: 9e2fd29864c5 ("rtw88: add napi support")
Signed-off-by: Jian-Hong Pan <[email protected]>
---
drivers/net/wireless/realtek/rtw88/pci.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c
index a7a6ebfaa203..a6fdddecd37d 100644
--- a/drivers/net/wireless/realtek/rtw88/pci.c
+++ b/drivers/net/wireless/realtek/rtw88/pci.c
@@ -1658,6 +1658,7 @@ static int rtw_pci_napi_poll(struct napi_struct *napi, int budget)
priv);
int work_done = 0;

+ rtw_pci_link_ps(rtwdev, false);
while (work_done < budget) {
u32 work_done_once;

@@ -1681,6 +1682,7 @@ static int rtw_pci_napi_poll(struct napi_struct *napi, int budget)
if (rtw_pci_get_hw_rx_ring_nr(rtwdev, rtwpci))
napi_schedule(napi);
}
+ rtw_pci_link_ps(rtwdev, true);

return work_done;
}
--
2.34.1

2021-12-13 09:04:39

by Ping-Ke Shih

Subject: RE: [PATCH] rtw88: pci: turn off PCI ASPM during NAPI polling

> -----Original Message-----
> From: Jian-Hong Pan <[email protected]>
> Sent: Monday, December 13, 2021 4:09 PM
> To: Pkshih <[email protected]>; Bernie Huang <[email protected]>; Kai-Heng Feng
> <[email protected]>; Yan-Hsuan Chuang <[email protected]>; Kalle Valo
> <[email protected]>
> Cc: [email protected]; [email protected]; [email protected];
> [email protected]; Jian-Hong Pan <[email protected]>
> Subject: [PATCH] rtw88: pci: turn off PCI ASPM during NAPI polling
>
> The system on the machines equipped with RTL8821CE freezes randomly
> until the PCI ASPM is disabled during NAPI poll function.
>
> Link: https://www.spinics.net/lists/linux-wireless/msg218387.html
> Fixes: 9e2fd29864c5 ("rtw88: add napi support")
> Signed-off-by: Jian-Hong Pan <[email protected]>
> ---
> drivers/net/wireless/realtek/rtw88/pci.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c
> index a7a6ebfaa203..a6fdddecd37d 100644
> --- a/drivers/net/wireless/realtek/rtw88/pci.c
> +++ b/drivers/net/wireless/realtek/rtw88/pci.c
> @@ -1658,6 +1658,7 @@ static int rtw_pci_napi_poll(struct napi_struct *napi, int budget)
> priv);
> int work_done = 0;
>
> + rtw_pci_link_ps(rtwdev, false);
> while (work_done < budget) {
> u32 work_done_once;
>
> @@ -1681,6 +1682,7 @@ static int rtw_pci_napi_poll(struct napi_struct *napi, int budget)
> if (rtw_pci_get_hw_rx_ring_nr(rtwdev, rtwpci))
> napi_schedule(napi);
> }
> + rtw_pci_link_ps(rtwdev, true);
>
> return work_done;
> }

I think we need to add ref_cnt and only do this thing on specific chip and platform [1].

[1] https://lore.kernel.org/linux-wireless/[email protected]/T/#m95b22af523ea801fdb84225b87a84ca4f04bb33d

--
Ping-Ke