cxgb4: fix eeprom len when diagnostics not implemented

[ Upstream commit 4ca110b ]

Ensure diagnostics monitoring support is implemented for the SFF 8472
compliant port module and set the correct length for ethtool port
module eeprom read.

Fixes: f56ec67 ("cxgb4: Add support for ethtool i2c dump")
Signed-off-by: Manoj Malviya <manojmalviya@chelsio.com>
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c

@@ -2011,12 +2011,15 @@ static int cxgb4_get_module_info(struct net_device *dev,
 		if (ret)
 			return ret;
 
-		if (!sff8472_comp || (sff_diag_type & 4)) {
+		if (!sff8472_comp || (sff_diag_type & SFP_DIAG_ADDRMODE)) {
 			modinfo->type = ETH_MODULE_SFF_8079;
 			modinfo->eeprom_len = ETH_MODULE_SFF_8079_LEN;
 		} else {
 			modinfo->type = ETH_MODULE_SFF_8472;
-			modinfo->eeprom_len = ETH_MODULE_SFF_8472_LEN;
+			if (sff_diag_type & SFP_DIAG_IMPLEMENTED)
+				modinfo->eeprom_len = ETH_MODULE_SFF_8472_LEN;
+			else
+				modinfo->eeprom_len = ETH_MODULE_SFF_8472_LEN / 2;
 		}
 		break;
 

drivers/net/ethernet/chelsio/cxgb4/t4_hw.h

@@ -293,6 +293,8 @@ enum {
 #define I2C_PAGE_SIZE		0x100
 #define SFP_DIAG_TYPE_ADDR	0x5c
 #define SFP_DIAG_TYPE_LEN	0x1
+#define SFP_DIAG_ADDRMODE	BIT(2)
+#define SFP_DIAG_IMPLEMENTED	BIT(6)
 #define SFF_8472_COMP_ADDR	0x5e
 #define SFF_8472_COMP_LEN	0x1
 #define SFF_REV_ADDR		0x1