Some r8168 NICs stop working upon system resume:

[  688.051096] r8169 0000:02:00.1 enp2s0f1: rtl_ep_ocp_read_cond == 0 (loop: 10, delay: 10000).
[  688.175131] r8169 0000:02:00.1 enp2s0f1: Link is Down
...
[  691.534611] r8169 0000:02:00.1 enp2s0f1: PCI error (cmd = 0x0407, status_errs = 0x0000)

Not sure if it's related, but those NICs have a BMC device at function
0:
02:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. Realtek RealManage BMC [10ec:816e] (rev 1a)

Trial and error shows that increase the loop wait on
rtl_ep_ocp_read_cond to 30 can eliminate the issue, so let
rtl8168ep_driver_start() to wait a bit longer.

Fixes: e6d6ca6e1204 ("r8169: Add support for another RTL8168FP")
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
v3:
 - Wording
 - Add Fixes tag
 - Denote 'net' in subject

v2:
 - Wording

 drivers/net/ethernet/realtek/r8169_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index bb787a52bc75..81fd31f6fac4 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -1211,7 +1211,7 @@ static void rtl8168ep_driver_start(struct rtl8169_private *tp)
 {
 	r8168ep_ocp_write(tp, 0x01, 0x180, OOB_CMD_DRIVER_START);
 	r8168ep_ocp_write(tp, 0x01, 0x30, r8168ep_ocp_read(tp, 0x30) | 0x01);
-	rtl_loop_wait_high(tp, &rtl_ep_ocp_read_cond, 10000, 10);
+	rtl_loop_wait_high(tp, &rtl_ep_ocp_read_cond, 10000, 30);
 }
 
 static void rtl8168_driver_start(struct rtl8169_private *tp)
-- 
2.34.1

On 22.12.2023 05:34, Kai-Heng Feng wrote:
> Some r8168 NICs stop working upon system resume:
> 
> [  688.051096] r8169 0000:02:00.1 enp2s0f1: rtl_ep_ocp_read_cond == 0 (loop: 10, delay: 10000).
> [  688.175131] r8169 0000:02:00.1 enp2s0f1: Link is Down
> ...
> [  691.534611] r8169 0000:02:00.1 enp2s0f1: PCI error (cmd = 0x0407, status_errs = 0x0000)
> 
> Not sure if it's related, but those NICs have a BMC device at function
> 0:
> 02:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. Realtek RealManage BMC [10ec:816e] (rev 1a)
> 
> Trial and error shows that increase the loop wait on
> rtl_ep_ocp_read_cond to 30 can eliminate the issue, so let
> rtl8168ep_driver_start() to wait a bit longer.
> 
> Fixes: e6d6ca6e1204 ("r8169: Add support for another RTL8168FP")
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> ---
> v3:
>  - Wording
>  - Add Fixes tag
>  - Denote 'net' in subject
> 
> v2:
>  - Wording
> 
>  drivers/net/ethernet/realtek/r8169_main.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
> index bb787a52bc75..81fd31f6fac4 100644
> --- a/drivers/net/ethernet/realtek/r8169_main.c
> +++ b/drivers/net/ethernet/realtek/r8169_main.c
> @@ -1211,7 +1211,7 @@ static void rtl8168ep_driver_start(struct rtl8169_private *tp)
>  {
>  	r8168ep_ocp_write(tp, 0x01, 0x180, OOB_CMD_DRIVER_START);
>  	r8168ep_ocp_write(tp, 0x01, 0x30, r8168ep_ocp_read(tp, 0x30) | 0x01);
> -	rtl_loop_wait_high(tp, &rtl_ep_ocp_read_cond, 10000, 10);
> +	rtl_loop_wait_high(tp, &rtl_ep_ocp_read_cond, 10000, 30);
>  }
>  
>  static void rtl8168_driver_start(struct rtl8169_private *tp)

Reviewed-by: Heiner Kallweit <hkallweit1@gmail.com>