[PATCH net-next v2] r8169: reset bus if NIC isn't accessible after tx timeout

[PATCH net-next v2] r8169: reset bus if NIC isn't accessible after tx timeout

[Heiner Kallweit]

ASPM issues may result in the NIC not being accessible any longer.
In this case disabling ASPM may not work. Therefore detect this case
by checking whether register reads return ~0, and try to make the
NIC accessible again by resetting the secondary bus.

v2:
- add exception handling for the case that pci_reset_bus() fails

Suggested-by: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/net/ethernet/realtek/r8169_main.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index 49c124d8e..02ef98a95 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -4535,6 +4535,16 @@ static void rtl_task(struct work_struct *work)
 		goto out_unlock;
 
 	if (test_and_clear_bit(RTL_FLAG_TASK_TX_TIMEOUT, tp->wk.flags)) {
+		/* if chip isn't accessible, reset bus to revive it */
+		if (RTL_R32(tp, TxConfig) == ~0) {
+			ret = pci_reset_bus(tp->pci_dev);
+			if (ret < 0) {
+				netdev_err(tp->dev, "Can't reset secondary PCI bus, detach NIC\n");
+				netif_device_detach(tp->dev);
+				goto out_unlock;
+			}
+		}
+
 		/* ASPM compatibility issues are a typical reason for tx timeouts */
 		ret = pci_disable_link_state(tp->pci_dev, PCIE_LINK_STATE_L1 |
 							  PCIE_LINK_STATE_L0S);
-- 
2.39.0

Re: [PATCH net-next v2] r8169: reset bus if NIC isn't accessible after tx timeout

[Alexander Duyck]

On Fri, Jan 13, 2023 at 2:46 PM Heiner Kallweit <hkallweit1@gmail.com> wrote:
>
> ASPM issues may result in the NIC not being accessible any longer.
> In this case disabling ASPM may not work. Therefore detect this case
> by checking whether register reads return ~0, and try to make the
> NIC accessible again by resetting the secondary bus.
>
> v2:
> - add exception handling for the case that pci_reset_bus() fails
>
> Suggested-by: Alexander Duyck <alexander.duyck@gmail.com>
> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
> ---
>  drivers/net/ethernet/realtek/r8169_main.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
> index 49c124d8e..02ef98a95 100644
> --- a/drivers/net/ethernet/realtek/r8169_main.c
> +++ b/drivers/net/ethernet/realtek/r8169_main.c
> @@ -4535,6 +4535,16 @@ static void rtl_task(struct work_struct *work)
>                 goto out_unlock;
>
>         if (test_and_clear_bit(RTL_FLAG_TASK_TX_TIMEOUT, tp->wk.flags)) {
> +               /* if chip isn't accessible, reset bus to revive it */
> +               if (RTL_R32(tp, TxConfig) == ~0) {
> +                       ret = pci_reset_bus(tp->pci_dev);
> +                       if (ret < 0) {
> +                               netdev_err(tp->dev, "Can't reset secondary PCI bus, detach NIC\n");
> +                               netif_device_detach(tp->dev);
> +                               goto out_unlock;
> +                       }
> +               }
> +
>                 /* ASPM compatibility issues are a typical reason for tx timeouts */
>                 ret = pci_disable_link_state(tp->pci_dev, PCIE_LINK_STATE_L1 |
>                                                           PCIE_LINK_STATE_L0S);

Looks good to me.

Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>

Re: [PATCH net-next v2] r8169: reset bus if NIC isn't accessible after tx timeout

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (master)
by David S. Miller <davem@davemloft.net>:

On Fri, 13 Jan 2023 23:46:19 +0100 you wrote:
> ASPM issues may result in the NIC not being accessible any longer.
> In this case disabling ASPM may not work. Therefore detect this case
> by checking whether register reads return ~0, and try to make the
> NIC accessible again by resetting the secondary bus.
> 
> v2:
> - add exception handling for the case that pci_reset_bus() fails
> 
> [...]

Here is the summary with links:
  - [net-next,v2] r8169: reset bus if NIC isn't accessible after tx timeout
    https://git.kernel.org/netdev/net-next/c/ce870af39558

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html