[PATCH net v4] r8169:fix "rtl_counters_cond == 1 (loop: 1000, delay: 10)" log spam.

[PATCH net v4] r8169:fix "rtl_counters_cond == 1 (loop: 1000, delay: 10)" log spam.

[Chunhao Lin]

There will be a log spam when there is no cable plugged. Please refer to
following links. https://bugzilla.kernel.org/show_bug.cgi?id=104351
https://bugzilla.kernel.org/show_bug.cgi?id=107421

This issue is caused by runtime power management. When there is no cable
plugged, the driver will be suspend (runtime suspend) by OS and NIC will be
put into the D3 state. During this time, if OS call rtl8169_get_stats64()
to dump tally counter, because NIC is in D3 state, the register value read
by driver will return all 0xff. This will let driver think tally counter
flag is not toggled and then sends the warning message "rtl_counters_cond
== 1 (loop: 1000, delay: 10)" to kernel log.

For fixing this issue, 1.add checking driver's pm runtime status in
rtl8169_get_stats64(). 2.dump tally counter before going runtime suspend
for counter accuracy in runtime suspend.

Signed-off-by: Chunhao Lin <hau@realtek.com>
---
 drivers/net/ethernet/realtek/r8169.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
index 537974c..4caeacb 100644
--- a/drivers/net/ethernet/realtek/r8169.c
+++ b/drivers/net/ethernet/realtek/r8169.c
@@ -7730,10 +7730,13 @@ rtl8169_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
 {
 	struct rtl8169_private *tp = netdev_priv(dev);
 	void __iomem *ioaddr = tp->mmio_addr;
+	struct pci_dev *pdev = tp->pci_dev;
 	struct rtl8169_counters *counters = tp->counters;
 	unsigned int start;
 
-	if (netif_running(dev))
+	pm_runtime_get_noresume(&pdev->dev);
+
+	if (netif_running(dev) && pm_runtime_active(&pdev->dev))
 		rtl8169_rx_missed(dev, ioaddr);
 
 	do {
@@ -7761,7 +7764,8 @@ rtl8169_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
 	 * Fetch additonal counter values missing in stats collected by driver
 	 * from tally counters.
 	 */
-	rtl8169_update_counters(dev);
+	if (pm_runtime_active(&pdev->dev))
+		rtl8169_update_counters(dev);
 
 	/*
 	 * Subtract values fetched during initalization.
@@ -7774,6 +7778,8 @@ rtl8169_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
 	stats->tx_aborted_errors = le16_to_cpu(counters->tx_aborted) -
 		le16_to_cpu(tp->tc_offset.tx_aborted);
 
+	pm_runtime_put_noidle(&pdev->dev);
+
 	return stats;
 }
 
@@ -7853,6 +7859,10 @@ static int rtl8169_runtime_suspend(struct device *device)
 
 	rtl8169_net_suspend(dev);
 
+	/* Update counters before going runtime suspend */
+	rtl8169_rx_missed(dev, tp->mmio_addr);
+	rtl8169_update_counters(dev);
+
 	return 0;
 }
 
-- 
1.9.1

Re: [PATCH net v4] r8169:fix "rtl_counters_cond == 1 (loop: 1000, delay: 10)" log spam.

[Francois Romieu]

Chunhao Lin <hau@realtek.com> :
[...]

Fine with me.

Is there any chance for the set of chipset dependent registers that
are safe to be read when in D3 state to be documented ?

-- 
Ueimor

RE: [PATCH net v4] r8169:fix "rtl_counters_cond == 1 (loop: 1000, delay: 10)" log spam.

[Hau]

> Fine with me.
> 
> Is there any chance for the set of chipset dependent registers that are safe to
> be read when in D3 state to be documented ?
> 

I think except registers in PCI configuration, all other registers should be read in D0 state.

------Please consider the environment before printing this e-mail.

Re: [PATCH net v4] r8169:fix "rtl_counters_cond == 1 (loop: 1000, delay: 10)" log spam.

[David Miller]

From: Chunhao Lin <hau@realtek.com>
Date: Wed, 24 Feb 2016 14:18:42 +0800

> There will be a log spam when there is no cable plugged. Please refer to
> following links. https://bugzilla.kernel.org/show_bug.cgi?id=104351
> https://bugzilla.kernel.org/show_bug.cgi?id=107421
> 
> This issue is caused by runtime power management. When there is no cable
> plugged, the driver will be suspend (runtime suspend) by OS and NIC will be
> put into the D3 state. During this time, if OS call rtl8169_get_stats64()
> to dump tally counter, because NIC is in D3 state, the register value read
> by driver will return all 0xff. This will let driver think tally counter
> flag is not toggled and then sends the warning message "rtl_counters_cond
> == 1 (loop: 1000, delay: 10)" to kernel log.
> 
> For fixing this issue, 1.add checking driver's pm runtime status in
> rtl8169_get_stats64(). 2.dump tally counter before going runtime suspend
> for counter accuracy in runtime suspend.
> 
> Signed-off-by: Chunhao Lin <hau@realtek.com>

Applied, thanks.