* Re: mips allmodconfig
[not found] <20110125143113.55aea198.akpm@linux-foundation.org>
@ 2011-01-28 7:34 ` Takashi Iwai
2011-01-30 16:04 ` Ralf Baechle
0 siblings, 1 reply; 2+ messages in thread
From: Takashi Iwai @ 2011-01-28 7:34 UTC (permalink / raw)
To: Ralf Baechle; +Cc: Andrew Morton, linux-mips
At Tue, 25 Jan 2011 14:31:13 -0800,
Andrew Morton wrote:
>
> sound/oss/soundcard.c:69: error: `MAX_DMA_CHANNELS' undeclared here (not in a function)
> sound/oss/soundcard.c:69: error: storage size of `dma_alloc_map' isn't known
> sound/oss/soundcard.c:69: warning: 'dma_alloc_map' defined but not used
>
> In case you happen to be interested in oss drivers ;)
I took a quick look. The only case where no MAX_DMA_CHANNELS is
defined is only MIPS with CONFIG_GENERIC_ISA_DMA_SUPPORT_BROKEN.
In arch/mips/include/asm/dma.h:
#ifndef CONFIG_GENERIC_ISA_DMA_SUPPORT_BROKEN
#define MAX_DMA_CHANNELS 8
#endif
What is the intention of this ifdef?
thanks,
Takashi (not interested but just bored ;)
^ permalink raw reply [flat|nested] 2+ messages in thread* Re: mips allmodconfig
2011-01-28 7:34 ` mips allmodconfig Takashi Iwai
@ 2011-01-30 16:04 ` Ralf Baechle
0 siblings, 0 replies; 2+ messages in thread
From: Ralf Baechle @ 2011-01-30 16:04 UTC (permalink / raw)
To: Takashi Iwai; +Cc: Andrew Morton, linux-mips
On Fri, Jan 28, 2011 at 08:34:22AM +0100, Takashi Iwai wrote:
> > sound/oss/soundcard.c:69: error: `MAX_DMA_CHANNELS' undeclared here (not in a function)
> > sound/oss/soundcard.c:69: error: storage size of `dma_alloc_map' isn't known
> > sound/oss/soundcard.c:69: warning: 'dma_alloc_map' defined but not used
> >
> > In case you happen to be interested in oss drivers ;)
>
> I took a quick look. The only case where no MAX_DMA_CHANNELS is
> defined is only MIPS with CONFIG_GENERIC_ISA_DMA_SUPPORT_BROKEN.
> In arch/mips/include/asm/dma.h:
>
> #ifndef CONFIG_GENERIC_ISA_DMA_SUPPORT_BROKEN
> #define MAX_DMA_CHANNELS 8
> #endif
>
> What is the intention of this ifdef?
Uh... It's a while, took a little headscratching until I remembered
again and I think the comment of aa414dff4f7bef29457592414551becdca72dd6b
is bogus ...
CONFIG_GENERIC_ISA_DMA enabled but MAX_DMA_CHANNELS disabled selects a
dummy version of the ISA DMA controller API. Some drivers don't have
correct dependencies or ifdefs on CONFIG_GENERIC_ISA_DMA or don't
have correct fallback strategies in case of CONFIG_GENERIC_ISA_DMA=n.
In those cases just leaving MAX_DMA_CHANNELS undefined is useful. This
is used on SGI Indigo² systems which have EISA slots but ISA DMA isn't
supported yet by Linux.
> Takashi (not interested but just bored ;)
Very interested boredom ;-)
Ralf
^ permalink raw reply [flat|nested] 2+ messages in thread
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[not found] <20110125143113.55aea198.akpm@linux-foundation.org>
2011-01-28 7:34 ` mips allmodconfig Takashi Iwai
2011-01-30 16:04 ` Ralf Baechle
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