From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Date: Tue, 18 Nov 2014 12:54:12 +0000 Subject: Re: [PATCH 08/25] ARM: shmobile: r8a7790: sound enables Audio DMAC peri peri entry on DTSI Message-Id: <15076656.0HaaBPou9k@wuerfel> List-Id: References: <1877842.49FtTfL2eK@wuerfel> <87a93pxtlr.wl%kuninori.morimoto.gx@renesas.com> In-Reply-To: <87a93pxtlr.wl%kuninori.morimoto.gx@renesas.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org On Tuesday 18 November 2014 00:03:50 Kuninori Morimoto wrote: > Hi Arnd > > > > "mem_src6", "src6_mem", > > > "mem_src7", "src7_mem", > > > "mem_src8", "src8_mem", > > > - "mem_src9", "src9_mem"; > > > + "mem_src9", "src9_mem", > > > + > > > + "src0_ssiu0", "src1_ssiu0", "src2_ssiu0", "src3_ssiu0", "src4_ssiu0", > > > + "src0_ssiu1", "src1_ssiu1", "src2_ssiu1", "src3_ssiu1", "src4_ssiu1", > > > + "src0_ssiu2", "src1_ssiu2", "src2_ssiu2", "src3_ssiu2", "src4_ssiu2", > > > > > > > I have to note that this looks rather weird and that none of the names > > are documented in the binding. > > > > Can you explain why this device uses over 100 DMA channels and put the > > exact naming rules into the binding? > > Do you expect all channels to be in use simultaneously? > > This device has 10 sound channels, and using 3 kind of IPs. > Then, data input/output needs DMA channel which needs specific ID to using. > Above name has ID pair for it, so there is much combination. > These specific ID is based on SoC, not board. > Sound driver / DMAEngine can get specific ID from above. > > Indeed binding itself was not documented yet. > I will add it ASAP. It sounds like you have some device-to-device DMAs here, which isn't supported by the generic dmaengine binding at all, and I don't think the driver currently attempts to use them. Is that correct? Could you try to remove those from the binding and just leave the device-to-memory and memory-to-device channels there? If we ever want to support those, we probably have to extend the dmaengine binding first, and then the driver binding would also look different. Arnd