phy: fix 10/100Mbps operation on 1Gbps-capable links

de1d786 [add support for Xilinx 1000BASE-X phy (GTX)] introduced a check for the extended status register in order to support 1Gbps-capable PHYs that don't have the 1000BASE-T registers. Since Extended Status only indicates what the PHY (i.e. the local side) is capable of, this broke communication with non-1Gbps peers. Only check the extended status if the 1000BASE-T registers are actually missing so we don't end up setting speed to 1Gbps even though the previous test (for the combination of local and peer support for 1Gbps) already indicated we can't do 1Gbps with the current peer. Signed-off-by: Sascha Silbe <t-uboot@infra-silbe.de> Tested-by: Fabio Estevam <fabio.estevam@freescale.com> Reviewed-by: Joe Hershberger <joe.hershberger@ni.com>

phy: fix 10/100Mbps operation on 1Gbps-capable links
de1d786 [add support for Xilinx 1000BASE-X phy (GTX)] introduced a check for the extended status register in order to support 1Gbps-capable PHYs that don't have the 1000BASE-T registers. Since Extended Status only indicates what the PHY (i.e. the local side) is capable of, this broke communication with non-1Gbps peers. Only check the extended status if the 1000BASE-T registers are actually missing so we don't end up setting speed to 1Gbps even though the previous test (for the combination of local and peer support for 1Gbps) already indicated we can't do 1Gbps with the current peer. Signed-off-by: Sascha Silbe <t-uboot@infra-silbe.de> Tested-by: Fabio Estevam <fabio.estevam@freescale.com> Reviewed-by: Joe Hershberger <joe.hershberger@ni.com>
Sascha Silbe · Tom Rini
1 parent 971c450a44
Showing 1 changed file with 9 additions and 1 deletions Side-by-side Diff
drivers/net/phy/phy.c
@@ -333,7 +333,15 @@
 		} else if (lpa & LPA_10FULL)
 			phydev->duplex = DUPLEX_FULL;
  
-		if (mii_reg & BMSR_ESTATEN)
+		/*
+		 * Extended status may indicate that the PHY supports
+		 * 1000BASE-T/X even though the 1000BASE-T registers
+		 * are missing. In this case we can't tell whether the
+		 * peer also supports it, so we only check extended
+		 * status if the 1000BASE-T registers are actually
+		 * missing.
+		 */
+		if ((mii_reg & BMSR_ESTATEN) && !(mii_reg & BMSR_ERCAP))
 			estatus = phy_read(phydev, MDIO_DEVAD_NONE,
 					   MII_ESTATUS);
...	...	@@ -333,7 +333,15 @@
333	333	} else if (lpa & LPA_10FULL)
334	334	phydev->duplex = DUPLEX_FULL;
335	335
336		- if (mii_reg & BMSR_ESTATEN)
	336	+ /*
	337	+ * Extended status may indicate that the PHY supports
	338	+ * 1000BASE-T/X even though the 1000BASE-T registers
	339	+ * are missing. In this case we can't tell whether the
	340	+ * peer also supports it, so we only check extended
	341	+ * status if the 1000BASE-T registers are actually
	342	+ * missing.
	343	+ */
	344	+ if ((mii_reg & BMSR_ESTATEN) && !(mii_reg & BMSR_ERCAP))
337	345	estatus = phy_read(phydev, MDIO_DEVAD_NONE,
338	346	MII_ESTATUS);
339	347