[PATCH 0/3] OMAP: DMA: mstandby mode and runtime pm support

[Kevin Hilman]

"G, Manjunath Kondaiah" <manjugk at ti.com> writes:

> On Fri, Mar 04, 2011 at 09:48:26AM +0530, G, Manjunath Kondaiah wrote:
>> On Thu, Mar 03, 2011 at 10:35:23AM -0800, Kevin Hilman wrote:
>> > "G, Manjunath Kondaiah" <manjugk at ti.com> writes:
>> > 
>> > > This patch series is remaining part of dma hwmod to support pm runtime 
>> > > and for handling mstandby mode for all applicable DMA mstandby mode errata.
>> > 
>> > This is still not runtime-suspending when I use my DMA test in linking
>> > mode.
>> > 
>> > If I put a large enough period between transfers, it should autosuspend
>> > during transfers.  It seems to do auto-suspend and resume once, but then
>> > it never suspends again.
>> > 
>> > I tested with my dmatest module[1], and loaded with:
>> > 
>> >   # insmod ./dmatest.ko linking=1 forever=1 forever_period=1024
>> > 
>> > Not only does it not auto-suspend between transfers (which I expected),
>> > it also doesn't suspend after removing the module which stops all active
>> > channels.
>> 
>> The normal chaining test cases are executed and which used to show the
>> proper status. Let me reproduce this issue with your test procedure.
>
> ok. I am able to reproduce this issue and fixed _get_sync usage in
> omap_start_dma if channel linking is used. Earlier it was handled for
> the cases with chaining API's. If linking is done without chaining
> API's, it will result in _get_sync and _put mismatch.

Great, glad you found it.

My DMA test module predates the existence of a chaining API, so I guess
that's part of the problem.  Glad it helped though.

> Thanks for the test case and I will be re posting the patches with the 
> above fix.

Thanks,

Kevin