linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] Revert "net: stmmac: Do not keep rearming the coalesce timer in stmmac_xmit"
@ 2018-08-24  9:04 Jerome Brunet
  2018-08-28  8:12 ` Jose Abreu
  2018-08-30  1:03 ` David Miller
  0 siblings, 2 replies; 7+ messages in thread
From: Jerome Brunet @ 2018-08-24  9:04 UTC (permalink / raw)
  To: Giuseppe Cavallaro, Alexandre Torgue, Jose Abreu, netdev
  Cc: Jerome Brunet, linux-kernel, linux-amlogic, Joao Pinto,
	Vitor Soares, Corentin Labbe

This reverts commit 4ae0169fd1b3c792b66be58995b7e6b629919ecf.

This change in the handling of the coalesce timer is causing regression on
(at least) amlogic platforms.

Network will break down very quickly (a few seconds) after starting
a download. This can easily be reproduced using iperf3 for example.

The problem has been reported on the S805, S905, S912 and A113 SoCs
(Realtek and Micrel PHYs) and it is likely impacting all Amlogics
platforms using Gbit ethernet

No problem was seen with the platform using 10/100 only PHYs (GXL internal)

Reverting change brings things back to normal and allows to use network
again until we better understand the problem with the coalesce timer.

Cc: Jose Abreu <joabreu@synopsys.com>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: Vitor Soares <soares@synopsys.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac.h      | 1 -
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 5 +----
 2 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index 76649adf8fb0..c0a855b7ab3b 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -112,7 +112,6 @@ struct stmmac_priv {
 	u32 tx_count_frames;
 	u32 tx_coal_frames;
 	u32 tx_coal_timer;
-	bool tx_timer_armed;
 
 	int tx_coalesce;
 	int hwts_tx_en;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index ff1ffb46198a..9f458bb16f2a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3147,16 +3147,13 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 	 * element in case of no SG.
 	 */
 	priv->tx_count_frames += nfrags + 1;
-	if (likely(priv->tx_coal_frames > priv->tx_count_frames) &&
-	    !priv->tx_timer_armed) {
+	if (likely(priv->tx_coal_frames > priv->tx_count_frames)) {
 		mod_timer(&priv->txtimer,
 			  STMMAC_COAL_TIMER(priv->tx_coal_timer));
-		priv->tx_timer_armed = true;
 	} else {
 		priv->tx_count_frames = 0;
 		stmmac_set_tx_ic(priv, desc);
 		priv->xstats.tx_set_ic_bit++;
-		priv->tx_timer_armed = false;
 	}
 
 	skb_tx_timestamp(skb);
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 7+ messages in thread
end of thread, other threads:[~2018-08-30  9:21 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-08-24  9:04 [PATCH] Revert "net: stmmac: Do not keep rearming the coalesce timer in stmmac_xmit" Jerome Brunet
2018-08-28  8:12 ` Jose Abreu
2018-08-29 13:56   ` Jose Abreu
2018-08-29 18:03   ` Martin Blumenstingl
2018-08-29 18:05     ` Martin Blumenstingl
2018-08-30  9:21     ` Jerome Brunet
2018-08-30  1:03 ` David Miller

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).