Re: [PATCH v1 12/12] serial: 8250_lpss: enable DMA on Intel Quark UART

From: Andy Shevchenko
Date: Mon Apr 11 2016 - 12:05:18 EST


On Mon, Apr 11, 2016 at 6:51 PM, Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:
> On Mon, Apr 11, 2016 at 6:33 PM, Bryan O'Donoghue
> <pure.logic@xxxxxxxxxxxxxxxxx> wrote:
>> On Thu, 2016-04-07 at 23:37 +0300, Andy Shevchenko wrote:
>>
>> Preface. I tried this on Galileo and it appears to work. I'll do some
>> throughput testing to verify but, initially the results are positive :)
>
> I submitted (and pushed into my branch) a bit changed version (see my v2).
>
>>> + lpss->dma_maxburst = 8;
>>
>> Are these dwords ? If those are bytes then the maxburst value looks
>> small. In the BSP the max burst is 32 bytes.
>
> max_burst is in items of given size (here is 32 bytes for memory and 8
> bytes for UART). I took this value from Quark BSP, but I'll be happy
> to adjust to more optimal values.

+Jarkko.

Oy vei, seems we don't set memory side of transfer neither in
8250_dma, nor in spi-pxa2xx-dma.

--
With Best Regards,
Andy Shevchenko