Messages in this thread |  | | Date | Tue, 29 May 2018 17:15:55 +0200 | From | Boris Brezillon <> | Subject | Re: [PATCH] mtd: nand: raw: atmel: add module param to avoid using dma |
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On Tue, 29 May 2018 18:01:40 +0300 Eugen Hristev <eugen.hristev@microchip.com> wrote:
> [...] > > > > > > I think you're missing something here. We use the DMA engine in memcpy > > mode (SRAM -> DRAM), not in device mode (dev -> DRAM or DRAM -> dev). > > So there's no dmas prop defined in the DT and there should not be. > > > > Regards, > > > > Boris > > > > Ok, so the memcpy SRAM <-> DRAM will hog the transfer between DRAM and > LCD if my understanding is correct. That's the DMA that Peter wants to > disable with his patch ? > > Then we can then try to force NFC SRAM DMA channels to use just DDR port > 1 or 2 for memcpy ?
You mean the dmaengine? According to "14.1.3 Master to Slave Access" that's already the case.
Only DMAC0 can access the NFC SRAM and it's done through DMAC0:IF0, then access to DDR is going through port DDR port 1 (DMAC0:IF1) or 2 (DMAC0:IF0).
> > I have also received a suggestion to try to increase the porches in > LCDC_LCDCFG3 .
Yep, Nicolas suggested something similar. Peter, can you try that?
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