Re: [PATCH] dmaengine: cppi41: Fix cppi41_dma_prep_slave_sg() when idle

From: Tony Lindgren <tony@atomide.com>
To: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: Dan Williams <dan.j.williams@intel.com>,
	Vinod Koul <vinod.koul@intel.com>,
	Alexandre Bailon <abailon@baylibre.com>,
	Andy Shevchenko <andy.shevchenko@gmail.com>,
	Bin Liu <b-liu@ti.com>, Daniel Mack <zonque@gmail.com>,
	Felipe Balbi <felipe.balbi@linux.intel.com>,
	George Cherian <george.cherian@ti.com>,
	Grygorii Strashko <grygorii.strashko@ti.com>,
	Johan Hovold <johan@kernel.org>,
	Peter Ujfalusi <peter.ujfalusi@ti.com>,
	Sekhar Nori <nsekhar@ti.com>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	dmaengine@vger.kernel.org, linux-usb@vger.kernel.org,
	linux-omap@vger.kernel.org,
	giulio.benetti@benettiengineering.com,
	Sebastian Reichel <sre@kernel.org>,
	Skvortsov <andrej.skvortzov@gmail.com>,
	Yegor Yefremov <yegorslists@googlemail.com>
Subject: Re: [PATCH] dmaengine: cppi41: Fix cppi41_dma_prep_slave_sg() when idle
Date: Wed, 23 Oct 2019 12:00:33 -0700	[thread overview]
Message-ID: <20191023190033.GP5610@atomide.com> (raw)
In-Reply-To: <6996a5de-215b-f9a2-1aeb-5eeed1b7cf8d@cogentembedded.com>

* Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> [191023 18:56]:
> On 10/23/2019 06:31 PM, Tony Lindgren wrote:
> > --- a/drivers/dma/ti/cppi41.c
> > +++ b/drivers/dma/ti/cppi41.c
> > @@ -586,9 +586,22 @@ static struct dma_async_tx_descriptor *cppi41_dma_prep_slave_sg(
> >  	enum dma_transfer_direction dir, unsigned long tx_flags, void *context)
> >  {
> >  	struct cppi41_channel *c = to_cpp41_chan(chan);
> > +	struct dma_async_tx_descriptor *txd = NULL;
> > +	struct cppi41_dd *cdd = c->cdd;
> >  	struct cppi41_desc *d;
> >  	struct scatterlist *sg;
> >  	unsigned int i;
> > +	int error;
> > +
> > +	error = pm_runtime_get(cdd->ddev.dev);
> > +	if (error < 0) {
> 
>    I'd call that variable 'status', comparison (error < 0) just doesn't look right.
> If it was *if* (error), it would have been more correct. 

Good suggestion, something to remember for next time.
In general error is widely used this way though:

$ git grep -A1 "error = " | grep "error < 0" | wc -l
425

Regards,

Tony