phylib: Fix auto-negotiation restart avoidance
A previous patch, 51e2a3846eab18711f4eb59cd0a4c33054e2980a, made
genphy_config_aneg() not restart aneg by calling genphy_restart_aneg() if
the advertisement hadn't changed.
But, genphy_restart_aneg() doesn't just restart aneg, it may also *enable*
aneg or un-isolate the PHY from the MII (those functions are controlled by
the same register). The code to avoid calling genphy_restart_aneg() didn't
consider this.
So, modify genphy_config_aneg() to also check if the PHY needs to have aneg
enabled or be un-isolated before deciding not to restart aneg.
This caused a problem with certain Davicom PHYs, as that driver isolates
the PHY (why?) before calling genphy_config_aneg() and expects the PHY to
be un-isolated by that function.
Signed-off-by: Trent Piepho <tpiepho@freescale.com>
Reported-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 8fb1fac..55bc24b2 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -564,20 +564,32 @@
*/
int genphy_config_aneg(struct phy_device *phydev)
{
- int result = 0;
+ int result;
- if (AUTONEG_ENABLE == phydev->autoneg) {
- int result = genphy_config_advert(phydev);
+ if (AUTONEG_ENABLE != phydev->autoneg)
+ return genphy_setup_forced(phydev);
- if (result < 0) /* error */
- return result;
+ result = genphy_config_advert(phydev);
- /* Only restart aneg if we are advertising something different
- * than we were before. */
- if (result > 0)
- result = genphy_restart_aneg(phydev);
- } else
- result = genphy_setup_forced(phydev);
+ if (result < 0) /* error */
+ return result;
+
+ if (result == 0) {
+ /* Advertisment hasn't changed, but maybe aneg was never on to
+ * begin with? Or maybe phy was isolated? */
+ int ctl = phy_read(phydev, MII_BMCR);
+
+ if (ctl < 0)
+ return ctl;
+
+ if (!(ctl & BMCR_ANENABLE) || (ctl & BMCR_ISOLATE))
+ result = 1; /* do restart aneg */
+ }
+
+ /* Only restart aneg if we are advertising something different
+ * than we were before. */
+ if (result > 0)
+ result = genphy_restart_aneg(phydev);
return result;
}