Unverified Commit da560097 authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Mark Brown
Browse files

spi: Check if transfer is mapped before calling DMA sync APIs 



The resent update to remove the orig_nents checks revealed
that not all DMA sync backends can cope with the unallocated
SG list, while supplying orig_nents == 0 (the commit 861370f4
("iommu/dma: force bouncing if the size is not cacheline-aligned"),
for example, makes that happen for the IOMMU case). It means
we have to check if the buffers are DMA mapped before trying
to sync them. Re-introduce that check in a form of calling
->can_dma() in the same way as it's done in the DMA mapping loop
for the SPI transfers.

Reported-by: default avatarNícolas F. R. A. Prado <nfraprado@collabora.com>
Reported-by: default avatarNeil Armstrong <neil.armstrong@linaro.org>
Closes: https://lore.kernel.org/r/8ae675b5-fcf9-4c9b-b06a-4462f70e1322@linaro.org
Closes: https://lore.kernel.org/all/d3679496-2e4e-4a7c-97ed-f193bd53af1d@notapiano


Fixes: 8cc3bad9 ("spi: Remove unneded check for orig_nents")
Suggested-by: default avatarNícolas F. R. A. Prado <nfraprado@collabora.com>
Tested-by: default avatarNícolas F. R. A. Prado <nfraprado@collabora.com>
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://msgid.link/r/20240522171018.3362521-3-andriy.shevchenko@linux.intel.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 9f788ba4

drivers/spi/spi.c

+13 −5
Original line number Diff line number Diff line
@@ -1311,7 +1311,7 @@ static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg) 
	return 0;

}



static void spi_dma_sync_for_device(struct spi_controller *ctlr,

static void spi_dma_sync_for_device(struct spi_controller *ctlr, struct spi_message *msg,

				    struct spi_transfer *xfer)

{

	struct device *rx_dev = ctlr->cur_rx_dma_dev;
@@ -1320,11 +1320,14 @@ static void spi_dma_sync_for_device(struct spi_controller *ctlr, 
	if (!ctlr->cur_msg_mapped)

		return;



	if (!ctlr->can_dma(ctlr, msg->spi, xfer))

		return;



	dma_sync_sgtable_for_device(tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);

	dma_sync_sgtable_for_device(rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);

}



static void spi_dma_sync_for_cpu(struct spi_controller *ctlr,

static void spi_dma_sync_for_cpu(struct spi_controller *ctlr, struct spi_message *msg,

				 struct spi_transfer *xfer)

{

	struct device *rx_dev = ctlr->cur_rx_dma_dev;
@@ -1333,6 +1336,9 @@ static void spi_dma_sync_for_cpu(struct spi_controller *ctlr, 
	if (!ctlr->cur_msg_mapped)

		return;



	if (!ctlr->can_dma(ctlr, msg->spi, xfer))

		return;



	dma_sync_sgtable_for_cpu(rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);

	dma_sync_sgtable_for_cpu(tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);

}
@@ -1350,11 +1356,13 @@ static inline int __spi_unmap_msg(struct spi_controller *ctlr, 
}



static void spi_dma_sync_for_device(struct spi_controller *ctrl,

				    struct spi_message *msg,

				    struct spi_transfer *xfer)

{

}



static void spi_dma_sync_for_cpu(struct spi_controller *ctrl,

				 struct spi_message *msg,

				 struct spi_transfer *xfer)

{

}
@@ -1626,10 +1634,10 @@ static int spi_transfer_one_message(struct spi_controller *ctlr, 
			reinit_completion(&ctlr->xfer_completion);



fallback_pio:

			spi_dma_sync_for_device(ctlr, xfer);

			spi_dma_sync_for_device(ctlr, msg, xfer);

			ret = ctlr->transfer_one(ctlr, msg->spi, xfer);

			if (ret < 0) {

				spi_dma_sync_for_cpu(ctlr, xfer);

				spi_dma_sync_for_cpu(ctlr, msg, xfer);



				if (ctlr->cur_msg_mapped &&

				   (xfer->error & SPI_TRANS_FAIL_NO_START)) {
@@ -1654,7 +1662,7 @@ static int spi_transfer_one_message(struct spi_controller *ctlr, 
					msg->status = ret;

			}



			spi_dma_sync_for_cpu(ctlr, xfer);

			spi_dma_sync_for_cpu(ctlr, msg, xfer);

		} else {

			if (xfer->len)

				dev_err(&msg->spi->dev,