[net,v2] gianfar: Fix Tx flow control deactivation

Message ID 1504511128-25294-1-git-send-email-claudiu.manoil@nxp.com
State Accepted
Delegated to: David Miller
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Series
  • [net,v2] gianfar: Fix Tx flow control deactivation
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Commit Message

Claudiu Manoil Sept. 4, 2017, 7:45 a.m.
The wrong register is checked for the Tx flow control bit,
it should have been maccfg1 not maccfg2.
This went unnoticed for so long probably because the impact is
hardly visible, not to mention the tangled code from adjust_link().
First, link flow control (i.e. handling of Rx/Tx link level pause frames)
is disabled by default (needs to be enabled via 'ethtool -A').
Secondly, maccfg2 always returns 0 for tx_flow_oldval (except for a few
old boards), which results in Tx flow control remaining always on
once activated.

Should be queued for -stable, thanks.

Fixes: 45b679c9a3ccd9e34f28e6ec677b812a860eb8eb ("gianfar: Implement PAUSE frame generation support")

Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
---
v2: "Fixes" tag formatting and removed CC: stable from comments.

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

Comments

David Miller Sept. 5, 2017, 9:35 p.m. | #1
From: Claudiu Manoil <claudiu.manoil@nxp.com>
Date: Mon, 4 Sep 2017 10:45:28 +0300

> The wrong register is checked for the Tx flow control bit,
> it should have been maccfg1 not maccfg2.
> This went unnoticed for so long probably because the impact is
> hardly visible, not to mention the tangled code from adjust_link().
> First, link flow control (i.e. handling of Rx/Tx link level pause frames)
> is disabled by default (needs to be enabled via 'ethtool -A').
> Secondly, maccfg2 always returns 0 for tx_flow_oldval (except for a few
> old boards), which results in Tx flow control remaining always on
> once activated.
> 
> Fixes: 45b679c9a3ccd9e34f28e6ec677b812a860eb8eb ("gianfar: Implement PAUSE frame generation support")
> 
> Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>

Please do not put an empty line between Fixes: and other tags.  All tags
are equal and should be in one uninterrupted block of text.

Applied, and queued up for -stable, thanks.

Patch

diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index c4b4b0a..5be52d8 100644
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -3687,7 +3687,7 @@  static noinline void gfar_update_link_state(struct gfar_private *priv)
 		u32 tempval1 = gfar_read(&regs->maccfg1);
 		u32 tempval = gfar_read(&regs->maccfg2);
 		u32 ecntrl = gfar_read(&regs->ecntrl);
-		u32 tx_flow_oldval = (tempval & MACCFG1_TX_FLOW);
+		u32 tx_flow_oldval = (tempval1 & MACCFG1_TX_FLOW);
 
 		if (phydev->duplex != priv->oldduplex) {
 			if (!(phydev->duplex))