Hi Christoph, On Fri, 2018-04-20 at 10:02 +0200, Christoph Hellwig wrote: > Switch to the generic noncoherent direct mapping implementation. > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> > --- > arch/arc/Kconfig | 4 + > arch/arc/include/asm/Kbuild | 1 + > arch/arc/include/asm/dma-mapping.h | 21 ----- > arch/arc/mm/dma.c | 141 +++-------------------------- > 4 files changed, 19 insertions(+), 148 deletions(-) > delete mode 100644 arch/arc/include/asm/dma-mapping.h > [snip] > @@ -135,7 +134,7 @@ static int arc_dma_mmap(struct device *dev, struct vm_area_struct *vma, > * CPU accesses page via normal paddr, thus needs to explicitly made > * consistent before each use > */ > -static void _dma_cache_sync(phys_addr_t paddr, size_t size, > +static void _dma_cache_sync(struct device *dev, phys_addr_t paddr size_t size, > enum dma_data_direction dir) Seems like there's a missing comma: ----------------------------------->8------------------------------------ --- a/arch/arc/mm/dma.c +++ b/arch/arc/mm/dma.c @@ -134,7 +134,7 @@ int arch_dma_mmap(struct device *dev, struct vm_area_struct *vma, * CPU accesses page via normal paddr, thus needs to explicitly made * consistent before each use */ -static void _dma_cache_sync(struct device *dev, phys_addr_t paddr size_t size, +static void _dma_cache_sync(struct device *dev, phys_addr_t paddr, size_t size, enum dma_data_direction dir) { switch (dir) { ----------------------------------->8------------------------------------ Which is actually strange as I would expect ARC code to be built by bots. Anyways with above fix I do see problems with both USB and Ethernet controllers on ARC HSDK board. ----------------------------------->8------------------------------------ usb 1-1: new high-speed USB device number 2 using ehci-platform usb 1-1: device descriptor read/64, error -32 usb 1-1: device descriptor read/64, error -32 usb 1-1: new high-speed USB device number 3 using ehci-platform usb 1-1: device descriptor read/64, error -32 usb 1-1: device descriptor read/64, error -32 usb usb1-port1: attempt power cycle usb 1-1: new high-speed USB device number 4 using ehci-platform usb 1-1: device not accepting address 4, error -32 usb 1-1: new high-speed USB device number 5 using ehci-platform usb 1-1: device not accepting address 5, error -32 ... # wget ftp://ftp.denx.de/pub/u-boot/u-boot-1.0.0.tar.bz2 Connecting to ftp.denx.de (81.169.202.6:21) wget: can't connect to remote host (81.169.202.6): No route to host ----------------------------------->8------------------------------------ Will all patches from the series reverted (i.e. with your base-line) all issues go away. I'll need to spend more time on checking what's actually wrong. -Alexey P.S. Note to my ARC colleagues - it's required to disable IO Coherency to get DMA ops really used, it could be obviously done with: ----------------------------------->8------------------------------------ --- a/arch/arc/mm/cache.c +++ b/arch/arc/mm/cache.c @@ -27,7 +27,7 @@ static int l2_line_sz; static int ioc_exists; -int slc_enable = 1, ioc_enable = 1; +int slc_enable = 1, ioc_enable = 0; unsigned long perip_base = ARC_UNCACHED_ADDR_SPACE; /* legacy value for boot */ unsigned long perip_end = 0xFFFFFFFF; /* legacy value */ ----------------------------------->8------------------------------------