This is a note to let you know that I've just added the patch titled
spi: Don't mark message DMA mapped when no transfer in it is
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
spi-don-t-mark-message-dma-mapped-when-no-transfer-i.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d88499bc76cd8e7cf8809b55860473f672c3e483
Author: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Date: Wed May 22 20:09:49 2024 +0300
spi: Don't mark message DMA mapped when no transfer in it is
[ Upstream commit 9f788ba457b45b0ce422943fcec9fa35c4587764 ]
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@xxxxxxxxxxxxxxx>
Link: https://msgid.link/r/20240522171018.3362521-2-andriy.shevchenko@xxxxxxxxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index b18ae50db1f52..0f9410ed48290 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -931,6 +931,7 @@ 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) {
if (!ctlr->can_dma(ctlr, msg->spi, xfer))
continue;
@@ -954,6 +955,9 @@ 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_msg_mapped = true;
