[PATCH 2/3] sfp: fix EEPROM reading in the case of non-SFF8472 SFPs

[Russell King]

The EEPROM reading was trying to read from the second EEPROM address
if we requested the last byte from the SFF8079 EEPROM, which caused a
failure when the second EEPROM is not present.  Discovered with a
S-RJ01 SFP module.  Fix this.

Fixes: 73970055450e ("sfp: add SFP module support")
Signed-off-by: Russell King <rmk+ker...@armlinux.org.uk>
---
 drivers/net/phy/sfp.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index 1a958c7b912d..ee6b2e041171 100644
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -724,20 +724,19 @@ static int sfp_module_eeprom(struct sfp *sfp, struct 
ethtool_eeprom *ee,
                len = min_t(unsigned int, last, ETH_MODULE_SFF_8079_LEN);
                len -= first;
 
-               ret = sfp->read(sfp, false, first, data, len);
+               ret = sfp_read(sfp, false, first, data, len);
                if (ret < 0)
                        return ret;
 
                first += len;
                data += len;
        }
-       if (first >= ETH_MODULE_SFF_8079_LEN &&
-           first < ETH_MODULE_SFF_8472_LEN) {
+       if (first < ETH_MODULE_SFF_8472_LEN && last > ETH_MODULE_SFF_8079_LEN) {
                len = min_t(unsigned int, last, ETH_MODULE_SFF_8472_LEN);
                len -= first;
                first -= ETH_MODULE_SFF_8079_LEN;
 
-               ret = sfp->read(sfp, true, first, data, len);
+               ret = sfp_read(sfp, true, first, data, len);
                if (ret < 0)
                        return ret;
        }
-- 
2.7.4