On Wed, Jul 11, 2018 at 3:04 PM, Boris Brezillon <boris.brezil...@bootlin.com> wrote: > On Wed, 11 Jul 2018 14:26:58 +0200 > Arnd Bergmann <a...@arndb.de> wrote: > >> Compile-testing this driver on x86 caused a link error: >> >> ERROR: "__phys_to_dma" [drivers/mtd/nand/raw/qcom_nandc.ko] undefined! >> >> The problem here is that the driver attempts to convert the physical >> address into the DMA controller as a dma_addr_t and calls phys_to_dma() >> to do the conversion. >> >> However, there is no generic way to convert a phys_addr_t into a dma_addr_t >> for anything other than RAM (which should use the dma-mapping API instead). >> The only correct use of phys_to_dma() instead is inside of the dma-mapping >> implementation. > > Should we use dma_map_resource() to do the phys_addr_t to dma_addr_t > conversion?
I had not seen that interface before, but yes, that does seem like the best way to do it here. Arnd