RE: Issues with i.MX SPI DMA transfers

Robin Gong
2019-03-28T07:21:35Z

> -----Original Message-----
> From: Igor Plyatov <plyatov@gmail.com>
> Sent: 2019年3月28日 15:04
> To: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> Cc: linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> linux-spi@vger.kernel.org; dl-linux-imx <linux-imx@nxp.com>; Fabio Estevam
> <festevam@gmail.com>; Pengutronix Kernel Team <kernel@pengutronix.de>;
> Sascha Hauer <s.hauer@pengutronix.de>; Shawn Guo
> <shawnguo@kernel.org>; Mark Brown <broonie@kernel.org>;
> dmaengine@vger.kernel.org; Vinod Koul <vkoul@kernel.org>; Dan Williams
> <dan.j.williams@intel.com>; Andy Duan <fugang.duan@nxp.com>; Han Xu
> <han.xu@nxp.com>; Robin Gong <yibin.gong@nxp.com>; Clark Wang
> <xiaoning.wang@nxp.com>
> Subject: Re: Issues with i.MX SPI DMA transfers
>
> Dear Uwe,
>
>
> > Hello Igor,
> >
> > On Wed, Mar 27, 2019 at 08:40:00PM +0300, Igor Plyatov wrote:
> >> please, help to resolve two issues with SPI DMA transfers at i.MX6Q
> >> platform.
> >>
> >> First issue is
> >>  [ 4465.008003] spi_master spi0: I/O Error in DMA RX
> >>
> >> Second issue is duplication for one of received bytes.
> >>
> >> Probably, these issues related to each one.
> > This is probably the same problem I hit some time ago. Check ERR009165
> > in the errata. You either need to disable DMA or need a fixed
> > sdma-Script.
>
> disabling of DMA is not an option, because high throughput required for SPI bus
> to communicate with DSPs.
>
> I'm aware of ERR009165, but as I write some minutes earlier to list,
> spi0 (alias for ecspi1) and spi1 (alias for ecspi2) work flawless, while
> spi4 (alias for ecspi5) fails very fast.
>
> Does same SDMA script used for all SPI interfaces or scripts are different?
No different handle inside sdma script for different ecspi port. Agree Uwe, your
duplicate data caught seems like ERR009165. Anyway I'll create ecspi patch for you
to try in these days.
>
> Best wishes.
>
> --
>
> Igor Plyatov