Re: commit 271e1b86e691 is breaking DMA uart on SoCFPGA

[Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>]

Hi,

On Thursday, February 18, 2016 07:07:28 PM 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?

drivers/tty/serial/samsung.c

> 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 fails (UART DMA doesn't work).

> 2) Checkout next-20160211 kernel tree and set src_maxburst and
> dst_maxburst to 1 inside UART driver to see is it works?

This succeeds (UART DMA works fine).

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