Re: [PATCH] m32r: add simple dma

[Sudip Mukherjee]

On Thursday 03 November 2016 07:13 PM, Andrew Morton wrote:
> On Sun, 30 Oct 2016 23:47:29 +0530 Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx> wrote:
>
> > On Friday 21 October 2016 08:59 AM, Andrew Morton wrote:
> > > On Sat,  8 Oct 2016 23:23:18 +0530 Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx> wrote:
> > >
> > > > Some builds of m32r were failing as it tried to build few drivers which
> > > > needed dma but m32r is not having dma support. Objections were raised
> > > > when it was tried to make those drivers depend on HAS_DMA.
> > >
> > > Huh.  What were these objections?  That sounds like the appropriate
> > > fix.  And I suggest that a summary of those objections be captured in
> > > this patch's changelog.
> >
> > Sorry for the delay in reply. Got busy in dayjob and relocation.
> >
> > I was asked to provide dma stubs instead of adding HAS_DMA in the Kconfig.
> >
> > http://www.spinics.net/lists/kernel/msg2277152.html
> >
> > And an old thread-
> > http://www.spinics.net/lists/alsa-devel/msg50931.html
> >
> > It appeared to me that instead of adding dma stubs and returning error
> > values from them it will be better to add dma_noop to m32r. Looking at
> > the simplicity of dma_noop it seems that it should work.
> > What will you suggest? Do i send v2 after adding the "dma stub" comment
> > and the link to the thread in the commit message or should I opt for dma
> > stub?
>
> Disabling DMA in Kconfig is the most cautious approach.  If someone
> cares then they will be able to runtime test the thing, so those people
> can implement dma_noop (or something else).
>
> On the other hand, we could just go ahead and wire up dma_noop and if
> someone later has problems with it, they will report or fix those
> problems.
>
> So, umm, I guess that wiring up dma_noop gets us further forward than
> simply disabling everything, so how about we do that?

Again sorry for the delayed reply. But I am all set now. Relocating from 
one country to another is a tough one.
Do I send you v2 of the patch with the links in the commit message?

Regards
Sudip