[PATCH 5.11 317/601] media: saa7134: use sg_dma_len when building pgtable

Greg Kroah-Hartman
2021-05-12T17:31:04Z

From: Tasos Sahanidis <tasos@tasossah.com>

[ Upstream commit 4e1cb753c04d74e06d7ca826ea0bcb02526af03e ]

The new AMD IOMMU DMA implementation concatenates sglist entries under
certain conditions, and because saa7134 accessed the length member
directly, it did not support this scenario.

This fixes IO_PAGE_FAULTs and choppy DMA audio by using the
sg_dma_len macro.

Fixes: be62dbf554c5 ("iommu/amd: Convert AMD iommu driver to the dma-iommu api")
Signed-off-by: Tasos Sahanidis <tasos@tasossah.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/media/pci/saa7134/saa7134-core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/pci/saa7134/saa7134-core.c b/drivers/media/pci/saa7134/saa7134-core.c
index 391572a6ec76..efb757d5168a 100644
--- a/drivers/media/pci/saa7134/saa7134-core.c
+++ b/drivers/media/pci/saa7134/saa7134-core.c
@@ -243,7 +243,7 @@ int saa7134_pgtable_build(struct pci_dev *pci, struct saa7134_pgtable *pt,

ptr = pt->cpu + startpage;
for (i = 0; i < length; i++, list = sg_next(list)) {
- for (p = 0; p * 4096 < list->length; p++, ptr++)
+ for (p = 0; p * 4096 < sg_dma_len(list); p++, ptr++)
*ptr = cpu_to_le32(sg_dma_address(list) +
list->offset + p * 4096);
}
--
2.30.2