6.6-stable review patch. If anyone has any objections, please let me know.
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From: Andy Shevchenko andriy.shevchenko@linux.intel.com
[ 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@linux.intel.com Link: https://msgid.link/r/20240522171018.3362521-2-andriy.shevchenko@linux.intel.... Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 76383ddbd6a6f..da15c3f388d1f 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1128,6 +1128,7 @@ 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; @@ -1157,6 +1158,9 @@ 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;