gianfar: Fix Tx flow control deactivation

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>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index c4b4b0a1bbf0a60b9d757811b19e45e44afd3685..5be52d89b182ec4d1c46cc692a0e446d6925c618 100644 (file)
--- 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))