This is a note to let you know that I've just added the patch titled i2c: at91: Initialize dma_buf in at91_twi_xfer() to the 5.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: i2c-at91-initialize-dma_buf-in-at91_twi_xfer.patch and it can be found in the queue-5.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit d47cea41fa4ea6bef84ba90c1d8dd8e801cd26dc Author: Nathan Chancellor <nathan@xxxxxxxxxx> Date: Thu May 5 08:27:38 2022 -0700 i2c: at91: Initialize dma_buf in at91_twi_xfer() [ Upstream commit 6977262c2eee111645668fe9e235ef2f5694abf7 ] Clang warns: drivers/i2c/busses/i2c-at91-master.c:707:6: warning: variable 'dma_buf' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] if (dev->use_dma) { ^~~~~~~~~~~~ drivers/i2c/busses/i2c-at91-master.c:717:27: note: uninitialized use occurs here i2c_put_dma_safe_msg_buf(dma_buf, m_start, !ret); ^~~~~~~ Initialize dma_buf to NULL, as i2c_put_dma_safe_msg_buf() is a no-op when the first argument is NULL, which will work for the !dev->use_dma case. Fixes: 03fbb903c8bf ("i2c: at91: use dma safe buffers") Link: https://github.com/ClangBuiltLinux/linux/issues/1629 Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx> Reviewed-by: Michael Walle <michael@xxxxxxxx> Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c index 5eca3b3bb609..c0c35785a0dc 100644 --- a/drivers/i2c/busses/i2c-at91-master.c +++ b/drivers/i2c/busses/i2c-at91-master.c @@ -656,7 +656,7 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num) unsigned int_addr_flag = 0; struct i2c_msg *m_start = msg; bool is_read; - u8 *dma_buf; + u8 *dma_buf = NULL; dev_dbg(&adap->dev, "at91_xfer: processing %d messages:\n", num);