[PATCH net-next] r8169: disable ASPM in case of tx timeout

[PATCH net-next] r8169: disable ASPM in case of tx timeout

[Heiner Kallweit]

There are still single reports of systems where ASPM incompatibilities
cause tx timeouts. It's not clear whom to blame, so let's disable
ASPM in case of a tx timeout.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/net/ethernet/realtek/r8169_main.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index a9dcc98b6..7b58da9aa 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -576,6 +576,7 @@ struct rtl8169_tc_offsets {
 enum rtl_flag {
 	RTL_FLAG_TASK_ENABLED = 0,
 	RTL_FLAG_TASK_RESET_PENDING,
+	RTL_FLAG_TASK_TX_TIMEOUT,
 	RTL_FLAG_MAX
 };
 
@@ -3931,7 +3932,7 @@ static void rtl8169_tx_timeout(struct net_device *dev, unsigned int txqueue)
 {
 	struct rtl8169_private *tp = netdev_priv(dev);
 
-	rtl_schedule_task(tp, RTL_FLAG_TASK_RESET_PENDING);
+	rtl_schedule_task(tp, RTL_FLAG_TASK_TX_TIMEOUT);
 }
 
 static int rtl8169_tx_map(struct rtl8169_private *tp, const u32 *opts, u32 len,
@@ -4532,7 +4533,14 @@ static void rtl_task(struct work_struct *work)
 	    !test_bit(RTL_FLAG_TASK_ENABLED, tp->wk.flags))
 		goto out_unlock;
 
+	if (test_and_clear_bit(RTL_FLAG_TASK_TX_TIMEOUT, tp->wk.flags)) {
+		/* ASPM compatibility issues are a typical reason for tx timeouts */
+		pci_disable_link_state(tp->pci_dev, PCIE_LINK_STATE_L1 | PCIE_LINK_STATE_L0S);
+		goto reset;
+	}
+
 	if (test_and_clear_bit(RTL_FLAG_TASK_RESET_PENDING, tp->wk.flags)) {
+reset:
 		rtl_reset_work(tp);
 		netif_wake_queue(tp->dev);
 	}
-- 
2.39.0

Re: [PATCH net-next] r8169: disable ASPM in case of tx timeout

[Stephen Hemminger]

On Wed, 28 Dec 2022 22:30:56 +0100
Heiner Kallweit <hkallweit1@gmail.com> wrote:

> There are still single reports of systems where ASPM incompatibilities
> cause tx timeouts. It's not clear whom to blame, so let's disable
> ASPM in case of a tx timeout.
> 
> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>

Wouldn't a log message be appropriate here.

	netdev_WARN_ONCE(tp->dev, "ASPM disabled on Tx timeout\n");

Re: [PATCH net-next] r8169: disable ASPM in case of tx timeout

[Heiner Kallweit]

On 28.12.2022 23:05, Stephen Hemminger wrote:
> On Wed, 28 Dec 2022 22:30:56 +0100
> Heiner Kallweit <hkallweit1@gmail.com> wrote:
> 
>> There are still single reports of systems where ASPM incompatibilities
>> cause tx timeouts. It's not clear whom to blame, so let's disable
>> ASPM in case of a tx timeout.
>>
>> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
> 
> Wouldn't a log message be appropriate here.
> 
> 	netdev_WARN_ONCE(tp->dev, "ASPM disabled on Tx timeout\n");

Right, that's something I could add. Message will be printed only
if return code of pci_disable_link_state() indicates success.
And I'd use netdev_warn_once() instead of netdev_WARN_ONCE(),
because net core prints a stack trace already in case of tx timeout.