Messages in this thread | | | From | Tomasz Figa <> | Date | Thu, 20 Dec 2018 12:23:46 +0900 | Subject | Re: [PATCH v5 2/2] media: usb: pwc: Don't use coherent DMA buffers for ISO transfer |
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On Wed, Dec 19, 2018 at 11:51 PM Christoph Hellwig <hch@infradead.org> wrote: > > On Wed, Dec 19, 2018 at 05:18:35PM +0900, Tomasz Figa wrote: > > The existing code that deals with dma_alloc_attrs() without > > DMA_ATTR_NON_CONSISTENT would just call dma_get_sgtable_attrs() like > > here: > > I know. And dma_get_sgtable_attrs is fundamentally flawed and we > need to kill this interface as it just can't worked with virtually > tagged cases. It is a prime example for an interface that looks > nice and simple but is plain wrong.
Got it, thanks.
I haven't been following the problems with virtually tagged cases, would you mind sharing some background, so that we can consider it when adding non-consistent allocations to VB2?
Best regards, Tomasz
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