Re: commit 271e1b86e691 is breaking DMA uart on SoCFPGA

From: Bartlomiej Zolnierkiewicz
Date: Wed Feb 24 2016 - 08:25:38 EST



Hi,

On Wednesday, February 24, 2016 02:01:59 PM Caesar Wang wrote:
> Hi,
>
> Thanks Dinh & Alexander for the intergration testing.
>
> ---
>
> @Dinh,
>
> Can you test it again with the patch[0]?
>
> patch[0]:
> https://patchwork.kernel.org/patch/8398511/

This fixes the problem for me (tested on Samsung Exynos4412 SoC
based Trats2 board).

You may add:

Tested-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>

to your patch.

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

> -
> Caesar
> å 2016å02æ23æ 23:14, Dinh Nguyen åé:
> > Hi,
> >
> > Sorry that I couldn't get to this sooner.
> >
> > On 02/18/2016 10:07 AM, Alexander Kochetkov wrote:
> >> Hello!
> >>
> >> Bartlomiej, could you please tell what uart driver is used on Samsung
> >> Exynos4412?
> >> Dinh, could you please tell what uart driver is used on SoCFPGA?
> >>
> > SoCFPGA is using the 8250_dw.c uart driver.
> >
> >> Could you make two test?
> >>
> >> 1) Checkout tree at commit 848e9776fee4 "dmaengine: pl330: support
> >> burst mode for
> >> dev-to-mem and mem-to-dev transmit", make it buildable and see is it
> >> works. In order to make in buildable remove bursts argument from the
> >> line:
> >>
> >> if (*bursts == 1)
> >> - return _bursts(pl330, dry_run, buf, pxs, 1);
> >> + return _bursts(dry_run, buf, pxs, 1);
> >>
> > This case still fails for me.
> >
> >> 2) Checkout next-20160211 kernel tree and set src_maxburst and
> >> dst_maxburst to 1 inside UART driver to see is it works?
> >>
> > This case works and the UART is able to operate in DMA mode.
> >
> > Dinh