Messages in this thread | | | Date | Wed, 18 Jan 2012 09:35:59 +0000 | From | Russell King - ARM Linux <> | Subject | Re: [PATCH 7/8] dmaengine/dw_dmac: Unmap all memory buffers after completion of slave transfers |
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On Tue, Jan 17, 2012 at 02:37:10PM +0530, Viresh Kumar wrote: > On 1/17/2012 2:22 PM, Linus Walleij wrote: > > Basically the driver using the dmaengine shall map/unmap buffers > > used for slave transfers, not the driver. > > > > I usually map them before setting up a transfer and unmaps them > > when egtting the callback from the DMA engine that the transfer is > > complete. > > > > You implemented similar stuff in amba-pl08x :) . > > if (!plchan->slave) > pl08x_unmap_buffers(txd);
Take a look at that. "If *NOT* slave, unmap the buffers". That is in keeping with what I've been saying. Slave transfers *do* *not* get automatic buffer unmapping.
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