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

["G, Manjunath Kondaiah" <manjugk@ti.com>]

On Mon, Mar 07, 2011 at 04:36:12PM +0530, G, Manjunath Kondaiah wrote:
> 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@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.
> 
> Thanks for the test case and I will be re posting the patches with the 
> above fix.
While testing your test case with off mode for scenario:
insmod ./dmatest.ko linking=1 forever=1 forever_period=1024 debug=1

the transfer after timer expiry will get corrupted once it comes out of
off mode. Debugging offmode issue... 

Trying to use omap_pm_get_dev_context_loss_count(dev) for checking
offmode count for context restore in omap_start_dma.

-Manjunath