From: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
Fix warning when running with CONFIG_DMA_API_DEBUG_SG=y by allocating a
device_dma_parameters structure and filling in the max segment size. The
size used is the result of a discussion with Renesas hardware engineers
and unfortunately not found in the datasheet.
renesas_sdhi_internal_dmac ee140000.sd: DMA-API: mapping sg segment
longer than device claims to support [len=126976] [max=65536]
Reported-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
[wsa: simplified some logic after validating intended dma_parms life cycle
and added comment]
Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
---
After discussing with DMA maintainers [1], this really seems the intended way
of using dma_parms. Took Niklas patch V2 and simplified the logic a bit more
given the information from above (but I'll still tackle the dangling pointer
issue in the DMA core seperately).
[1] https://www.spinics.net/lists/iommu/msg29861.html
drivers/mmc/host/renesas_sdhi_internal_dmac.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/mmc/host/renesas_sdhi_internal_dmac.c b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
index ca0b43973769..e0823acaa3c2 100644
--- a/drivers/mmc/host/renesas_sdhi_internal_dmac.c
+++ b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
@@ -309,12 +309,20 @@ static const struct soc_device_attribute gen3_soc_whitelist[] = {
static int renesas_sdhi_internal_dmac_probe(struct platform_device *pdev)
{
const struct soc_device_attribute *soc = soc_device_match(gen3_soc_whitelist);
+ struct device *dev = &pdev->dev;
if (!soc)
return -ENODEV;
global_flags |= (unsigned long)soc->data;
+ dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms), GFP_KERNEL);
+ if (!dev->dma_parms)
+ return -ENOMEM;
+
+ /* value is max of SD_SECCNT. Confirmed by HW engineers */
+ dma_set_max_seg_size(dev, 0xffffffff);
+
return renesas_sdhi_probe(pdev, &renesas_sdhi_internal_dmac_dma_ops);
}
--
2.11.0
