On Sat, Dec 21, 2019 at 11:49:48AM +0100, Daniel Wagner wrote:
From: Arnd Bergmann arnd@arndb.de
[ Upstream commit 84092996673211f16ef3b942a191d7952e9dfea9 ]
The davinci_cpdma mixes up physical addresses as seen from the CPU and DMA addresses as seen from a DMA master, since it can operate on both normal memory or an on-chip buffer. If dma_addr_t is different from phys_addr_t, this means we get a compile-time warning about the type mismatch:
ethernet/ti/davinci_cpdma.c: In function 'cpdma_desc_pool_create': ethernet/ti/davinci_cpdma.c:182:48: error: passing argument 3 of 'dma_alloc_coherent' from incompatible pointer type [-Werror=incompatible-pointer-types] pool->cpumap = dma_alloc_coherent(dev, size, &pool->phys, In file included from ethernet/ti/davinci_cpdma.c:21:0: dma-mapping.h:398:21: note: expected 'dma_addr_t * {aka long long unsigned int *}' but argument is of type 'phys_addr_t * {aka unsigned int *}' static inline void *dma_alloc_coherent(struct device *dev, size_t size,
This slightly restructures the code so the address we use for mapping RAM into a DMA address is always a dma_addr_t, avoiding the warning. The code is correct even if both types are 32-bit because the DMA master in this device only supports 32-bit addressing anyway, independent of the types that are used.
We still assign this value to pool->phys, and that is wrong if the driver is ever used with an IOMMU, but that value appears to be never used, so there is no problem really. I've added a couple of comments about where we do things that are slightly violating the API.
Signed-off-by: Arnd Bergmann arnd@arndb.de Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Daniel Wagner dwagner@suse.de
Hi,
Pavel reported this fix is needed for the CIP kernel.
Since this patch was added to v4.5, we only need to backport to v4.4.
Now queued up, thanks.
greg k-h