Commit c8ed4918 authored Jan 13, 2023 by Serge Semin Committed by Lorenzo Pieralisi Jan 27, 2023

dmaengine: dw-edma: Don't permit non-inc interleaved xfers

The DW eDMA controller always increments both source and destination
addresses. Permitting DMA interleaved transfers with no src_inc/dst_inc
flags set may lead to unexpected behaviour for the device users.

Terminate interleaved transfers if at least one of the
dma_interleaved_template.{src_inc,dst_inc} flag is initialized to "false".

Note that in addition, we need to increase the source and destination
addresses after each iteration.

Link: https://lore.kernel.org/r/20230113171409.30470-6-Sergey.Semin@baikalelectronics.ru

Fixes: 85e7518f ("dmaengine: dw-edma: Add device_prep_interleave_dma() support")
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>

parent 13b6299c

drivers/dma/dw-edma/dw-edma-core.c

+6 −6

Original line number	Diff line number	Diff line
		@@ -385,6 +385,8 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
		return NULL;
		if (xfer->xfer.il->numf > 0 && xfer->xfer.il->frame_size > 0)
		return NULL;
		if (!xfer->xfer.il->src_inc \|\| !xfer->xfer.il->dst_inc)
		return NULL;
		} else {
		return NULL;
		}
		@@ -484,17 +486,15 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
		struct dma_interleaved_template *il = xfer->xfer.il;
		struct data_chunk *dc = &il->sgl[i];

		if (il->src_sgl) {
		src_addr += burst->sz;
		if (il->src_sgl)
		src_addr += dmaengine_get_src_icg(il, dc);
		}

		if (il->dst_sgl) {
		dst_addr += burst->sz;
		if (il->dst_sgl)
		dst_addr += dmaengine_get_dst_icg(il, dc);
		}
		}
		}

		return vchan_tx_prep(&chan->vc, &desc->vd, xfer->flags);