diff mbox series

[v1,1/2] spi: Don't mark message DMA mapped when no transfer in it is

Message ID 20240522171018.3362521-2-andriy.shevchenko@linux.intel.com (mailing list archive)
State Accepted
Commit 9f788ba457b45b0ce422943fcec9fa35c4587764
Headers show
Series soi: Don't call DMA sync API when not needed | expand

Commit Message

Andy Shevchenko May 22, 2024, 5:09 p.m. UTC 
There is no need to set the DMA mapped flag of the message if it has
no mapped transfers. Moreover, it may give the code a chance to take
the wrong paths, i.e. to exercise DMA related APIs on unmapped data.
Make __spi_map_msg() to bail earlier on the above mentioned cases.

Fixes: 99adef310f68 ("spi: Provide core support for DMA mapping transfers")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/spi/spi.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index b2efd4964f7c..51811f04e463 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1243,6 +1243,7 @@  static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
 	else
 		rx_dev = ctlr->dev.parent;
 
+	ret = -ENOMSG;
 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
 		/* The sync is done before each transfer. */
 		unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC;
@@ -1272,6 +1273,9 @@  static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
 			}
 		}
 	}
+	/* No transfer has been mapped, bail out with success */
+	if (ret)
+		return 0;
 
 	ctlr->cur_rx_dma_dev = rx_dev;
 	ctlr->cur_tx_dma_dev = tx_dev;