PHY: Avoid unnecessary aneg restarts
authorTrent Piepho <tpiepho@freescale.com>
Wed, 24 Sep 2008 10:55:46 +0000 (10:55 +0000)
committerDavid S. Miller <davem@davemloft.net>
Wed, 8 Oct 2008 22:43:54 +0000 (15:43 -0700)
commit51e2a3846eab18711f4eb59cd0a4c33054e2980a
treea9abbddd407ce2205218148ebdcf8f54709f6a1c
parent7bf6bf4803df1adc927f585168d2135fb019c698
PHY: Avoid unnecessary aneg restarts

The PHY's aneg is configured and restarted whenever the link is brought up,
e.g. when DHCP is started after the kernel has booted.  This can take the
link down for several seconds while auto-negotiation is redone.

If the advertised features haven't changed, then it shouldn't be necessary
to bring down the link and start auto-negotiation over again.

genphy_config_advert() is enhanced to return 0 when the advertised features
haven't been changed and >0 when they have been.

genphy_config_aneg() then uses this information to not call
genphy_restart_aneg() if there has been no change.

Signed-off-by: Trent Piepho <tpiepho@freescale.com>
Acked-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/phy/phy_device.c