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.
Cc: stable@vger.kernel.org Signed-off-by: Michael Walle michael@walle.cc ---
I'm not sure if or which Fixes: tag I should add to this patch. The issue seems to be since a very long time, but nobody seem to have triggered it. FWIW, I'm using the sff,sfp driver, which triggers this.
drivers/i2c/busses/i2c-at91-master.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c index b0eae94909f4..a7a22fedbaba 100644 --- a/drivers/i2c/busses/i2c-at91-master.c +++ b/drivers/i2c/busses/i2c-at91-master.c @@ -656,6 +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;
dev_dbg(&adap->dev, "at91_xfer: processing %d messages:\n", num);
@@ -703,7 +704,18 @@ 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: