From mboxrd@z Thu Jan 1 00:00:00 1970 From: linux@arm.linux.org.uk (Russell King - ARM Linux) Date: Mon, 29 Jun 2015 11:08:04 +0100 Subject: dma-mapping: support for DMA_ATTR_NON_CONSISTENT DMA attribute In-Reply-To: References: <20150628224543.GW7557@n2100.arm.linux.org.uk> <5590E962.4020700@topic.nl> Message-ID: <20150629100804.GA7557@n2100.arm.linux.org.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Jun 29, 2015 at 12:05:09PM +0200, Sylvain Munaut wrote: > Well that can't be since the dma_sync_* are part of streaming API and > the dma_alloc_attrs is part of the "coherent" API (even though you > have the NON_COHERENT flag in it ... that's a bit weird). > > But I don't see the alternative, unless the doc is suggesting I > basically do all the cache invalidation myself manually and doing arch > specific stuff directly in the driver ? Maybe someone with this problem should work on a solution - augmenting the coherent API with a set of functions to do what you want? Please, if you find something lacking like this, make a proposal and send a patch - but bear in mind that such an extension is not a matter for just ARM, but every other architecture that the kernel supports, so merely sending it to ARM mailing lists isn't going to get you very far. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net.