Re: commit 271e1b86e691 is breaking DMA uart on SoCFPGA

[Dinh Nguyen <dinguyen@opensource.altera.com>]

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