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: sta...@vger.kernel.org
Signed-off-by: Michael Walle <mich...@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:
--
2.30.2
