From: Nathan Chancellor nathan@kernel.org
stable inclusion from stable-v5.10.121 commit f57696bc63418642f0f262ad8baded7d1192296f category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6CQ
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ 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@kernel.org Reviewed-by: Michael Walle michael@walle.cc Signed-off-by: Wolfram Sang wsa@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- drivers/i2c/busses/i2c-at91-master.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c index 974225faaf96..7960fa4b8c5b 100644 --- a/drivers/i2c/busses/i2c-at91-master.c +++ b/drivers/i2c/busses/i2c-at91-master.c @@ -657,7 +657,7 @@ 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);