mlxsw: i2c: Limit single transaction buffer size

[ Upstream commit d7248f1cc835bd80e936dc5b2d94b149bdd0077d ]

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: 3029a693beda ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/mellanox/mlxsw/i2c.c b/drivers/net/ethernet/mellanox/mlxsw/i2c.c
index d23734ecb416ab78b7ed390dc305548eac92eb37..4fac27c36ad85b5b8ec3bfee7c324ae117f6ede4 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlxsw/i2c.c
+++ b/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 {