Re: [PATCH 2/2] dmaengine: cppi41: Add basic PM runtime support

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi,

* Vinod Koul <vinod.koul@xxxxxxxxx> [160821 23:34]:
> On Fri, Aug 19, 2016 at 03:59:40PM -0700, Tony Lindgren wrote:
> @@ -349,6 +358,12 @@ static dma_cookie_t cppi41_tx_submit(struct dma_async_tx_descriptor *tx)
> >  static int cppi41_dma_alloc_chan_resources(struct dma_chan *chan)
> >  {
> >  	struct cppi41_channel *c = to_cpp41_chan(chan);
> > +	struct cppi41_dd *cdd = c->cdd;
> > +	int error;
> > +
> > +	error = pm_runtime_get_sync(cdd->ddev.dev);
> 
> This will be problematic. The alloc callback are not supposed to sleep, so
> we cannot use a _sync() call here :(
> 
> This is explicitly documented in Documentation/dmaengine/provider.txt

Hmm but for device_alloc_chan_resources and device_free_chan_resources
we have "These functions can sleep" in the documentation?

Maybe you got confused with the patch @@ line saying cppi41_tx_submit
although the pm_runtime_get is in cppi41_dma_alloc_chan_resources?
Or else I'm confused :)

Anyways, if necessary we could move the call to cppi_writel out of
cppi41_dma_alloc_chan_resources I think.

Regards,

Tony
--
To unsubscribe from this list: send the line "unsubscribe dmaengine" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Kernel]     [Linux ARM (vger)]     [Linux ARM MSM]     [Linux Omap]     [Linux Arm]     [Linux Tegra]     [Fedora ARM]     [Linux for Samsung SOC]     [eCos]     [Linux PCI]     [Linux Fastboot]     [Gcc Help]     [Git]     [DCCP]     [IETF Announce]     [Security]     [Linux MIPS]     [Yosemite Campsites]

  Powered by Linux