Re: Issues with i.MX SPI DMA transfers

[Igor Plyatov]

Dear Robin,

I have applied patches 
0001-dma-engine-imx-sdma-add-mcu_2_ecspi-script.patch, 
0002-spi-spi-imx-fix-ERR009165.patch and made testing.

Results are following:

root@cr7:~# spidev_test -D /dev/spidev0.0 -s 12000000 -b 8 -S 512 -I 
10000000000 -l
spi mode: 0x20
bits per word: 8
max speed: 12000000 Hz (12000 KHz)
[Â 133.987798] spi_imx 2008000.spi: I/O Error in DMA TX
[Â 133.992810] spidev spi0.0: SPI transfer failed: -110
[Â 133.997860] spi_master spi0: failed to transfer one message from queue
can't send spi message: Connection timed out
Aborted (core dumped)

root@cr7:~# spidev_test -D /dev/spidev1.0 -s 12000000 -b 8 -S 512 -I 
10000000000 -l
spi mode: 0x20
bits per word: 8
max speed: 12000000 Hz (12000 KHz)
[Â 483.530815] spi_imx 200c000.spi: I/O Error in DMA TX
[Â 483.535825] spidev spi1.0: SPI transfer failed: -110
[Â 483.540873] spi_master spi1: failed to transfer one message from queue
can't send spi message: Connection timed out
Aborted (core dumped)

root@cr7:~# spidev_test -D /dev/spidev4.0 -s 12000000 -b 8 -S 512 -I 
10000000000 -l
spi mode: 0x20
bits per word: 8
max speed: 12000000 Hz (12000 KHz)
[ÂÂ 94.228774] spi_imx 2018000.spi: I/O Error in DMA TX
[ÂÂ 94.233788] spidev spi4.0: SPI transfer failed: -110
[ÂÂ 94.238837] spi_master spi4: failed to transfer one message from queue
can't send spi message: Connection timed out
Aborted (core dumped)

Best wishes.

--

Igor Plyatov


> Hi Igor,
> 	Please have a try with the attached patch, assume you have already used the sdma firmware
>  From https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/tree/imx/sdma/sdma-imx6q.bin
> > -----Original Message-----
> > From: Igor Plyatov <plyatov@xxxxxxxxx>
> > Sent: 2019å3æ28æ 15:04
> > To: Uwe Kleine-KÃnig <u.kleine-koenig@xxxxxxxxxxxxxx>
> > Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx;
> > linux-spi@xxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>; Fabio Estevam
> > <festevam@xxxxxxxxx>; Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>;
> > Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>; Shawn Guo
> > <shawnguo@xxxxxxxxxx>; Mark Brown <broonie@xxxxxxxxxx>;
> > dmaengine@xxxxxxxxxxxxxxx; Vinod Koul <vkoul@xxxxxxxxxx>; Dan Williams
> > <dan.j.williams@xxxxxxxxx>; Andy Duan <fugang.duan@xxxxxxx>; Han Xu
> > <han.xu@xxxxxxx>; Robin Gong <yibin.gong@xxxxxxx>; Clark Wang
> > <xiaoning.wang@xxxxxxx>
> > 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
> > > >   Â[ 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?
> >
> > Best wishes.
> >
> > --
> >
> > Igor Plyatov