Re: [PATCH] swiotlb: sync buffer when mapping FROM_DEVICE

2019-05-22 Thread Marek Szyprowski
Hi Robin, On 2019-05-22 15:55, Robin Murphy wrote: > On 22/05/2019 14:34, Christoph Hellwig wrote: >> On Wed, May 22, 2019 at 02:25:38PM +0100, Robin Murphy wrote: >>> Sure, but that should be irrelevant since the effective problem here >>> is in >>> the sync_*_for_cpu direction, and it's the unm

Re: [PATCH] swiotlb: sync buffer when mapping FROM_DEVICE

2019-05-22 Thread Robin Murphy
On 2019-05-22 2:09 pm, Christoph Hellwig wrote: On Wed, May 22, 2019 at 01:50:47PM +0100, Robin Murphy wrote: Would that work out any different from the existing DMA_ATTR_SKIP_CPU_SYNC? If drivers are prepared to handle this issue from their end, they can already do so for single mappings by us

Re: [PATCH] swiotlb: sync buffer when mapping FROM_DEVICE

2019-05-22 Thread Christoph Hellwig
On Wed, May 22, 2019 at 01:50:47PM +0100, Robin Murphy wrote: > Would that work out any different from the existing DMA_ATTR_SKIP_CPU_SYNC? > > If drivers are prepared to handle this issue from their end, they can > already do so for single mappings by using that attr along with explicit > parti