[PATCH AUTOSEL for 4.14 32/67] sfp: fix EEPROM reading in the case of non-SFF8472 SFPs

Sasha Levin
2018-03-08T04:58:59Z

From: Russell King <rmk+kernel@armlinux.org.uk>

[ Upstream commit 2794ffc441dde3109804085dc745e8014a4de224 ]

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+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
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 8bf10aba7452..ddf184db9c45 100644
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -667,20 +667,19 @@ 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;
}
--
2.14.1