From: Andy Shevchenko Date: Wed, 22 May 2024 17:09:49 +0000 (+0300) Subject: spi: Don't mark message DMA mapped when no transfer in it is X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9f788ba457b4;p=linux.git spi: Don't mark message DMA mapped when no transfer in it is 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 --- diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index a8966caed8414..d40ce0fdb1a81 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;