On 13 September 2018 at 16:47, Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> wrote: > 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> Applied for next, thanks! Kind regards Uffe > --- > > 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 >
