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spi: Don't mark message DMA mapped when no transfer in it is

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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: 99adef310f ("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.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Andy Shevchenko 2024-05-22 20:09:49 +03:00 committed by Mark Brown
parent d6e7ffd482
commit 9f788ba457
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1 changed files with 4 additions and 0 deletions
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4
drivers/spi/spi.c
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@ -1243,6 +1243,7 @@ static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
else else
rx_dev = ctlr->dev.parent; rx_dev = ctlr->dev.parent;
ret = -ENOMSG;
list_for_each_entry(xfer, &msg->transfers, transfer_list) { list_for_each_entry(xfer, &msg->transfers, transfer_list) {
/* The sync is done before each transfer. */ /* The sync is done before each transfer. */
unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC; 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_rx_dma_dev = rx_dev;
ctlr->cur_tx_dma_dev = tx_dev; ctlr->cur_tx_dma_dev = tx_dev;