i2c: at91: Initialize dma_buf in at91_twi_xfer()

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: 03fbb903c8 ("i2c: at91: use dma safe buffers")
Link: https://github.com/ClangBuiltLinux/linux/issues/1629
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Michael Walle <michael@walle.cc>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
This commit is contained in:
Nathan Chancellor 2022-05-05 08:27:38 -07:00 committed by Wolfram Sang
parent a181b8d187
commit 6977262c2e

View File

@ -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);