On Tue, Aug 27, 2019 at 04:45:20PM +0900, Masahiro Yamada wrote: > On Mon, Aug 26, 2019 at 4:33 PM Christoph Hellwig <hch@xxxxxx> wrote: > > > > On Mon, Aug 26, 2019 at 11:05:00AM +0900, Masahiro Yamada wrote: > > > This is included in v5.3-rc6 > > > so I tested it. > > > > So there is no allocation failure, but you get I/O errors later? > > Right. > > > > > Does the device use a device-private CMA area? > > Not sure. > My driver is drivers/mmc/host/sdhci-cadence.c > It reuses routines in drivers/mmc/host/sdhci.c > > > > > Does it work with Linux > > 5.2 if CONFIG_DMA_CMA is disabled? > > No. > 5.2 + disable CONFIG_DMA_CMA > failed in the same way. So it seems like the device wants CMA memory. I guess the patch below will fix it, but that isn't the solution. Can you try it to confirm? In the end it probably assumes a dma mask it doesn't set that the CMA memory satisfies or something similar. diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c index 69cfb4345388..bd2f24aa7f19 100644 --- a/kernel/dma/contiguous.c +++ b/kernel/dma/contiguous.c @@ -236,7 +236,7 @@ struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp) if (dev && dev->cma_area) cma = dev->cma_area; - else if (count > 1) + else cma = dma_contiguous_default_area; /* CMA can be used only in the context which permits sleeping */
