From eede5fcca70e2dda5c5ba29e9098f9f35cda2408 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Wed, 22 May 2024 20:09:49 +0300 Subject: [PATCH] spi: Don't mark message DMA mapped when no transfer in it is BugLink: https://bugs.launchpad.net/bugs/2073603 [ 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 Link: https://msgid.link/r/20240522171018.3362521-2-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin Signed-off-by: Portia Stephens Signed-off-by: Roxana Nicolescu --- drivers/spi/spi.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index a7194f29c200..8bb0e6cb5a7b 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1222,6 +1222,7 @@ 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; @@ -1251,6 +1252,9 @@ 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;