diff mbox series

[v1,2/2] spi: Check if transfer is mapped before calling DMA sync APIs

Message ID 20240522171018.3362521-3-andriy.shevchenko@linux.intel.com
State Accepted
Commit da560097c05612f8d360f86528f6213629b9c395
Headers show
Series None | expand

Commit Message

Andy Shevchenko May 22, 2024, 5:09 p.m. UTC 
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 861370f49ce4
("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: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Reported-by: Neil 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: 8cc3bad9d9d6 ("spi: Remove unneded check for orig_nents")
Suggested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/spi/spi.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

Comments

Mark Brown May 23, 2024, 12:01 p.m. UTC | #1 
On Wed, May 22, 2024 at 02:41:48PM -0400, Nícolas F. R. A. Prado wrote:

> I tested this series and I still get the oops (attached at the end for
> reference). When I tried this change originally, I added it on top of the
> patches you had supplied. And as it turns out one of them was necessary.
> Specifically, if I add 
> 
> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> index f94420858c22..9bc9fd10d538 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -1220,6 +1220,11 @@ void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
>         spi_unmap_buf_attrs(ctlr, dev, sgt, dir, 0);

The other two patches are already queued, could you send this one
incrementally please Andy?
diff mbox series

Patch

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 51811f04e463..cc8bb7d5ba1a 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -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,