From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH] dma: cpp41: Fix handling of error path Date: Tue, 15 Nov 2016 12:58:17 -0800 Message-ID: <20161115205816.GN4082@atomide.com> References: <20161111192852.25399-1-tony@atomide.com> <8d1e380a-ec75-3893-ea50-65e1526d58ea@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <8d1e380a-ec75-3893-ea50-65e1526d58ea-l0cyMroinI0@public.gmane.org> Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sekhar Nori Cc: Dan Williams , Vinod Koul , Bin Liu , Daniel Mack , Felipe Balbi , Johan Hovold , Peter Ujfalusi , Sebastian Andrzej Siewior , dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-omap@vger.kernel.org * Sekhar Nori [161115 00:35]: > On Saturday 12 November 2016 12:58 AM, Tony Lindgren wrote: > > If we return early on pm_runtime_get() error, we need to also call > > pm_runtime_put_noidle() as pointed out in a musb related thread > > by Johan Hovold . This is to keep the PM runtime > > use counts happy. > > > > Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") > > Cc: Johan Hovold > > Signed-off-by: Tony Lindgren > > --- > > drivers/dma/cppi41.c | 11 +++++++++-- > > 1 file changed, 9 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/dma/cppi41.c b/drivers/dma/cppi41.c > > --- a/drivers/dma/cppi41.c > > +++ b/drivers/dma/cppi41.c > > @@ -366,8 +366,11 @@ static int cppi41_dma_alloc_chan_resources(struct dma_chan *chan) > > int error; > > > > error = pm_runtime_get_sync(cdd->ddev.dev); > > - if (error < 0) > > + if (error < 0) { > > + pm_runtime_put_noidle(cdd->ddev.dev); > > + > > If pm_runtime_get_sync() fails due to callback error, then > rpm_callback() sets dev.power.runtime_error to an error value which gets > cleared by an explicit call to pm_runtime_set_suspended(). > > This will tell the framework that the status of device is suspended. > Else, the failure will be sticky and on subsequent attempts, > rpm_resume() will keep returning early instead of trying to resume the > device again. > > This is as far as I can gather from code. So, I believe the recovery > path should be: > > if (error < 0) { > pm_runtime_set_suspended(cdd->ddev.dev); > pm_runtime_put_noidle(cdd->ddev.dev); > > ... Well we should test this :) BTW, what other users of cppi41 do we have in addition to musb? I think davinci is or will be using it too? Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html