From bdb59f949d663b7e943fb5f40b2557af4314abf9 Mon Sep 17 00:00:00 2001 From: Trent Piepho Date: Thu, 30 Oct 2008 18:17:07 -0700 Subject: [PATCH] gianfar: Don't reset TBI<->SerDes link if it's already up The link may be up already via the chip's reset strapping, or though action of U-Boot, or from the last time the interface was brought up. Resetting the link causes it to go down for several seconds. This can significantly increase the time from power-on to DHCP completion and a device being accessible to the network. Signed-off-by: Trent Piepho Acked-by: Andy Fleming Signed-off-by: Jeff Garzik --- drivers/net/gianfar.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c index 249541a1814..83a5cb6aa23 100644 --- a/drivers/net/gianfar.c +++ b/drivers/net/gianfar.c @@ -591,6 +591,14 @@ static void gfar_configure_serdes(struct net_device *dev) if (bus) mutex_lock(&bus->mdio_lock); + /* If the link is already up, we must already be ok, and don't need to + * configure and reset the TBI<->SerDes link. Maybe U-Boot configured + * everything for us? Resetting it takes the link down and requires + * several seconds for it to come back. + */ + if (gfar_local_mdio_read(regs, tbipa, MII_BMSR) & BMSR_LSTATUS) + goto done; + /* Single clk mode, mii mode off(for serdes communication) */ gfar_local_mdio_write(regs, tbipa, MII_TBICON, TBICON_CLK_SELECT); @@ -601,6 +609,7 @@ static void gfar_configure_serdes(struct net_device *dev) gfar_local_mdio_write(regs, tbipa, MII_BMCR, BMCR_ANENABLE | BMCR_ANRESTART | BMCR_FULLDPLX | BMCR_SPEED1000); + done: if (bus) mutex_unlock(&bus->mdio_lock); } -- 2.41.1