From: Vadim Pasternak Date: Thu, 24 Aug 2023 13:43:08 +0000 (+0200) Subject: mlxsw: i2c: Fix chunk size setting in output mailbox buffer X-Git-Tag: v6.4.16~484 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b97bbe83461b5e2e16068aa864c1098c4a88f434;p=thirdparty%2Fkernel%2Fstable.git 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 --- diff --git a/drivers/net/ethernet/mellanox/mlxsw/i2c.c b/drivers/net/ethernet/mellanox/mlxsw/i2c.c index 2c586c2308aef..d23734ecb416a 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/i2c.c +++ b/drivers/net/ethernet/mellanox/mlxsw/i2c.c @@ -444,7 +444,7 @@ 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");