From: Michael Walle michael@walle.cc
[ Upstream commit 03fbb903c8bf7e53e101e8d9a7b261264317c411 ]
The supplied buffer might be on the stack and we get the following error message: [ 3.312058] at91_i2c e0070600.i2c: rejecting DMA map of vmalloc memory
Use i2c_{get,put}_dma_safe_msg_buf() to get a DMA-able memory region if necessary.
Fixes: 60937b2cdbf9 ("i2c: at91: add dma support") Signed-off-by: Michael Walle michael@walle.cc Reviewed-by: Codrin Ciubotariu codrin.ciubotariu@microchip.com Signed-off-by: Wolfram Sang wsa@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/i2c/busses/i2c-at91-master.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c index 66864f9cf7ac..974225faaf96 100644 --- a/drivers/i2c/busses/i2c-at91-master.c +++ b/drivers/i2c/busses/i2c-at91-master.c @@ -657,6 +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;
dev_dbg(&adap->dev, "at91_xfer: processing %d messages:\n", num);
@@ -704,7 +705,17 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num) dev->msg = m_start; dev->recv_len_abort = false;
+ if (dev->use_dma) { + dma_buf = i2c_get_dma_safe_msg_buf(m_start, 1); + if (!dma_buf) { + ret = -ENOMEM; + goto out; + } + dev->buf = dma_buf; + } + ret = at91_do_twi_transfer(dev); + i2c_put_dma_safe_msg_buf(dma_buf, m_start, !ret);
ret = (ret < 0) ? ret : num; out: