On 2021/10/5 3:52, Jason Gunthorpe wrote: > On Mon, Sep 27, 2021 at 08:59:13AM -0300, Jason Gunthorpe wrote: >> On Sun, Sep 26, 2021 at 02:11:15PM +0800, Cai Huoqing wrote: >>> Replacing kmalloc/kfree/dma_map_single/dma_unmap_single() >>> with dma_alloc_coherent/dma_free_coherent() helps to reduce >>> code size, and simplify the code, and coherent DMA will not >>> clear the cache every time. >>> >>> Signed-off-by: Cai Huoqing <caihuoqing@xxxxxxxxx> >>> drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 20 +++++--------------- >>> 1 file changed, 5 insertions(+), 15 deletions(-) >> >> Given I don't see any dma_sync_single calls for this mapping, isn't >> this a correctness fix too? > > HNS folks? > > Jason > . > Our SoC can keep cache coherent, so there is no exception even if dma_sync_single* is not called, but the driver should not make assumptions about SoC. So using dma_alloc_coherent() instead of kmalloc/dma_map_single() can simplify the code and achieve the same purpose. Wenpeng Liang
