Re: [PATCH v2] sh: Update dma-sh api

[Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>]

Paul Mundt wrote:
> On Tue, Mar 10, 2009 at 01:48:14PM +0900, Nobuhiro Iwamatsu wrote:
>> diff --git a/arch/sh/include/asm/dma.h b/arch/sh/include/asm/dma.h
>> index beca712..085e05a 100644
>> --- a/arch/sh/include/asm/dma.h
>> +++ b/arch/sh/include/asm/dma.h
>> @@ -23,12 +23,8 @@
>>  /* But... */
>>  /* XXX: This is not applicable to SuperH, just needed for alloc_bootmem */
>>  #define MAX_DMA_ADDRESS		(PAGE_OFFSET+0x10000000)
>> -
>> -#ifdef CONFIG_NR_DMA_CHANNELS
>> -#  define MAX_DMA_CHANNELS	(CONFIG_NR_DMA_CHANNELS)
>> -#else
>> -#  define MAX_DMA_CHANNELS	(CONFIG_NR_ONCHIP_DMA_CHANNELS)
>> -#endif
>> +/* MAX DMA Channel */
>> +#define MAX_DMA_CHANNELS	(CONFIG_NR_ONCHIP_DMA_CHANNELS)

Thank you for your comments.


>>
> This breaks the Dreamcast, which contains multiple DMACs and needs more
> than the on-chip channels managed by the DMA API. As the Dreamcast is the
> primary user of this code, please make sure you do not break its use of
> the API. It would also be good if someone can verify whether the G2 and
> PVR2 DMA still work after this patch is applied.

OK. I will fix this point.
> 
> On the other hand, I don't know how much we really want to be doing here
> in the first place. All new development should be happening on the
> dmaengine API instead, this code is mostly for keeping the existing users
> limping along, and not much else. Matt Fleming was doing some work there,
> it would be preferable to see that code updated and merged rather than
> work spent on the old DMA API.
> 

I see.
I have already been writing the driver of DMAengine, and I am testing.
To make old DMA-API coexist with dma engine in these patches, I wrote.

Best regards,
  Nobuhiro