mlxsw: i2c: Limit single transaction buffer size

Maximum size of buffer is obtained from underlying I2C adapter and in
case adapter allows I2C transaction buffer size greater than 100 bytes,
transaction will fail due to firmware limitation.

As a result driver will fail initialization.

Limit the maximum size of transaction buffer by 100 bytes to fit to
firmware.

Remove unnecessary calculation:
max_t(u16, MLXSW_I2C_BLK_DEF, quirk_size).
This condition can not happened.

Fixes: 3029a69 ("mlxsw: i2c: Allow flexible setting of I2C transactions size")
Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/i2c.c

@@ -48,6 +48,7 @@
 #define MLXSW_I2C_MBOX_SIZE_BITS	12
 #define MLXSW_I2C_ADDR_BUF_SIZE		4
 #define MLXSW_I2C_BLK_DEF		32
+#define MLXSW_I2C_BLK_MAX		100
 #define MLXSW_I2C_RETRY			5
 #define MLXSW_I2C_TIMEOUT_MSECS		5000
 #define MLXSW_I2C_MAX_DATA_SIZE		256
@@ -653,7 +654,7 @@ static int mlxsw_i2c_probe(struct i2c_client *client)
 			return -EOPNOTSUPP;
 		}
 
-		mlxsw_i2c->block_size = max_t(u16, MLXSW_I2C_BLK_DEF,
+		mlxsw_i2c->block_size = min_t(u16, MLXSW_I2C_BLK_MAX,
 					      min_t(u16, quirks->max_read_len,
 						    quirks->max_write_len));
 	} else {