Messages in this thread | | | Date | Mon, 13 Jan 2020 16:12:53 +0100 | From | Christoph Hellwig <> | Subject | Re: [PATCH 1/2] MIPS: Define pgprot_dmacoherent according to coherentio status |
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On Mon, Jan 13, 2020 at 11:11:58PM +0800, Jiaxun Yang wrote: > > > 于 2020年1月13日 GMT+08:00 下午10:58:20, Christoph Hellwig <hch@lst.de> 写到: > >On Mon, Jan 13, 2020 at 10:07:04PM +0800, Jiaxun Yang wrote: > >> For MIPS chips that support coherentio DMA, it's always safe > >> to make DMA requests cached. > > > >For DMA coherent devices pgprot_dmacoherent isn't even used, so this > >doesn't make sense. > > Hi, > > I'm supposed to use it later in drm/ttm > ttm_bo_util to overwrite pgprot for TTM_PL_SYSTEM. > And I wish this pgropt can always represent dmacoherent pgropt. > Would it be fine?
No code outside the core DMA code has any business using pgprot_dmacoherent.
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