mlxsw: spectrum: Fix EEPROM access in case of SFP/SFP+

The current code does not handle correctly the access to the upper page
in case of SFP/SFP+ EEPROM. In that case the offset should be local
and the I2C address should be changed.

Fixes: 2ea109039cd3 ("mlxsw: spectrum: Add support for access cable info via ethtool")
Reported-by: Florian Klink <flokli@flokli.de>
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index ed7cd6c..e080459 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -2545,7 +2545,9 @@ out:
        return err;
 }
 
-#define MLXSW_SP_QSFP_I2C_ADDR 0x50
+#define MLXSW_SP_I2C_ADDR_LOW 0x50
+#define MLXSW_SP_I2C_ADDR_HIGH 0x51
+#define MLXSW_SP_EEPROM_PAGE_LENGTH 256
 
 static int mlxsw_sp_query_module_eeprom(struct mlxsw_sp_port *mlxsw_sp_port,
                                        u16 offset, u16 size, void *data,
@@ -2554,12 +2556,25 @@ static int mlxsw_sp_query_module_eeprom(struct mlxsw_sp_port *mlxsw_sp_port,
        struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
        char eeprom_tmp[MLXSW_SP_REG_MCIA_EEPROM_SIZE];
        char mcia_pl[MLXSW_REG_MCIA_LEN];
+       u16 i2c_addr;
        int status;
        int err;
 
        size = min_t(u16, size, MLXSW_SP_REG_MCIA_EEPROM_SIZE);
+
+       if (offset < MLXSW_SP_EEPROM_PAGE_LENGTH &&
+           offset + size > MLXSW_SP_EEPROM_PAGE_LENGTH)
+               /* Cross pages read, read until offset 256 in low page */
+               size = MLXSW_SP_EEPROM_PAGE_LENGTH - offset;
+
+       i2c_addr = MLXSW_SP_I2C_ADDR_LOW;
+       if (offset >= MLXSW_SP_EEPROM_PAGE_LENGTH) {
+               i2c_addr = MLXSW_SP_I2C_ADDR_HIGH;
+               offset -= MLXSW_SP_EEPROM_PAGE_LENGTH;
+       }
+
        mlxsw_reg_mcia_pack(mcia_pl, mlxsw_sp_port->mapping.module,
-                           0, 0, offset, size, MLXSW_SP_QSFP_I2C_ADDR);
+                           0, 0, offset, size, i2c_addr);
 
        err = mlxsw_reg_query(mlxsw_sp->core, MLXSW_REG(mcia), mcia_pl);
        if (err)