From b2d7f0f313b8a4767d4600a7f83b7ae6c5f8d44f Mon Sep 17 00:00:00 2001 From: Vadim Pasternak Date: Thu, 24 Aug 2023 15:43:08 +0200 Subject: [PATCH] mlxsw: i2c: Fix chunk size setting in output mailbox buffer [ Upstream commit 146c7c330507c0384bf29d567186632bfe975927 ] The driver reads commands output from the output mailbox. If the size of the output mailbox is not a multiple of the transaction / block size, then the driver will not issue enough read transactions to read the entire output, which can result in driver initialization errors. Fix by determining the number of transactions using DIV_ROUND_UP(). Fixes: 3029a693beda ("mlxsw: i2c: Allow flexible setting of I2C transactions size") Signed-off-by: Vadim Pasternak Reviewed-by: Ido Schimmel Signed-off-by: Petr Machata Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/mellanox/mlxsw/i2c.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/mellanox/mlxsw/i2c.c b/drivers/net/ethernet/mellanox/mlxsw/i2c.c index 7cc4c30af1a7..65976a3ab591 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/i2c.c +++ b/drivers/net/ethernet/mellanox/mlxsw/i2c.c @@ -427,7 +427,7 @@ mlxsw_i2c_cmd(struct device *dev, u16 opcode, u32 in_mod, size_t in_mbox_size, } else { /* No input mailbox is case of initialization query command. */ reg_size = MLXSW_I2C_MAX_DATA_SIZE; - num = reg_size / mlxsw_i2c->block_size; + num = DIV_ROUND_UP(reg_size, mlxsw_i2c->block_size); if (mutex_lock_interruptible(&mlxsw_i2c->cmd.lock) < 0) { dev_err(&client->dev, "Could not acquire lock");