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From: Viresh Kumar <viresh.kumar@linaro.org>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Hein Tibosch <hein_tibosch@yahoo.es>,
	Andrew Morton <akpm@linux-foundation.org>,
	Hans-Christian Egtvedt <egtvedt@samfundet.no>,
	Arnd Bergmann <arnd.bergmann@linaro.org>,
	spear-devel <spear-devel@list.st.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"ludovic.desroches" <ludovic.desroches@atmel.com>,
	Havard Skinnemoen <havard@skinnemoen.net>,
	Nicolas Ferre <nicolas.ferre@atmel.com>
Subject: Re: [PATCH v4 2/3] dw_dmac: max_mem_width limits value for SRC/DST_TR_WID register
Date: Mon, 3 Sep 2012 14:00:11 +0530	[thread overview]
Message-ID: <CAKohpo=bvzm1O4FAtsr3YpLg-w1Rp7RT-9ZuJBgVZRxVHnQO_g@mail.gmail.com> (raw)
In-Reply-To: <CAHp75VcQOeVeKPg8z9u+fd8ia4QAyrq6UQn-D7Q-yO9+pLS6LQ@mail.gmail.com>

On 3 September 2012 13:55, Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
>> #define DW_MEM_WIDTH_64         0       /* default */
>> #define DW_MEM_WIDTH_32         1       /* e.g. for avr32 */
> There are 4 options: 32, 64, 128, and 256 bits. I would prefer to see
> the value in conjunction with
> real value in the register, namely 2 for 32, 3 - 64, 4 - 128, 5 - 256.

Which register are you talking about? This configuration is outside of DMAC
controller and i am not sure if dw DMAC controller can do 128 or 256
bit transfers.

>> @@ -58,6 +58,9 @@ struct dw_dma_slave {
>>         u32                     cfg_lo;
>>         u8                      src_master;
>>         u8                      dst_master;
>> +#define        DW_MEM_WIDTH_64         0
>> +#define        DW_MEM_WIDTH_32         1       /* e.g. for avr32 */
>> +       u8                      max_mem_width;
> Might be I missed something, but why is it slave configuration?
> I think the controller (actually channel) structure is more suitable
> to keep that field inside.

@Hein: Even i missed it. How will you do memcpy transfers as we don't have
this structure there. Probably you need to move this to DMA controller platform
data filed.

viresh

  reply	other threads:[~2012-09-03  8:30 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-02 17:54 Hein Tibosch
2012-09-03  8:25 ` Andy Shevchenko
2012-09-03  8:30   ` Viresh Kumar [this message]
2012-09-03  8:49     ` Andy Shevchenko
2012-09-03  8:59       ` Viresh Kumar
2012-09-03 13:06         ` Hein Tibosch
2012-09-04  6:38           ` Andy Shevchenko

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