On Wed, Jul 19, 2023 at 06:15:59AM -0400, Michael S. Tsirkin wrote: > A recent patchset highlighted to me that DMA_ATTR_SKIP_CPU_SYNC > might be easily misunderstood. .. just curious: what patchset is that? DMA_ATTR_SKIP_CPU_SYNC is often a bad idea and all users probably could use a really good audit.. > #define DMA_ATTR_NO_KERNEL_MAPPING (1UL << 4) > /* > - * DMA_ATTR_SKIP_CPU_SYNC: Allows platform code to skip synchronization of > - * the CPU cache for the given buffer assuming that it has been already > - * transferred to 'device' domain. > + * DMA_ATTR_SKIP_CPU_SYNC: Allows platform code to skip synchronization of the > + * CPU and device domains for the given buffer. While we're at it, I think "allows" is the wrong word here, we really must skip the synchronization or else we're in trouble.
