Re: [PATCH v7 24/30] net: wan: Add framer framework support

[Herve Codina]

Hi Jakub

On Fri, 6 Oct 2023 15:08:10 -0700
Jakub Kicinski <kuba@xxxxxxxxxx> wrote:

> On Thu, 28 Sep 2023 09:06:42 +0200 Herve Codina wrote:
> > +menu "Framer Subsystem"
> > +
> > +config GENERIC_FRAMER
> > +	bool "Framer Core"
> > +	help
> > +	  Generic Framer support.
> > +	  A framer is a component in charge of an E1/T1 line interface.
> > +	  Connected usually to a TDM bus, it converts TDM frames to/from E1/T1
> > +	  frames. It also provides information related to the E1/T1 line.
> > +	  Used with HDLC, the network can be reached through the E1/T1 line.
> > +
> > +	  This framework is designed to provide a generic interface for framer
> > +	  devices present in the kernel. This layer will have the generic
> > +	  API by which framer drivers can create framer using the framer
> > +	  framework and framer users can obtain reference to the framer.
> > +	  All the users of this framework should select this config.  
> 
> maybe make the menu a menuconfig with info about framers but hide 
> the GENERIC_FRAMER symbol? The driver 'select' it anyway, what's
> the point of prompting the user..

Yes, I will change in the next iteration.

> 
> > +	if (WARN_ON(!dev))
> > +		return ERR_PTR(-EINVAL);  
> 
> no defensive programming, let the kernel crash

Will be changed.

> 
> > +	ret = framer_pm_runtime_get_sync(framer);
> > +	if (ret < 0 && ret != -EOPNOTSUPP)
> > +		goto err_pm_sync;
> > +
> > +	ret = 0; /* Override possible ret == -EOPNOTSUPP */  
> 
> This looks pointless given that ret is either overwritten or not used
> later on

Indeed. Will be removed in the next iteration.

> 
> > +	mutex_lock(&framer->mutex);
> > +	if (framer->power_count == 0 && framer->ops->power_on) {
> > +		ret = framer->ops->power_on(framer);
> > +		if (ret < 0) {
> > +			dev_err(&framer->dev, "framer poweron failed --> %d\n", ret);
> > +			goto err_pwr_on;
> > +		}
> > +	}
> > +	++framer->power_count;
> > +	mutex_unlock(&framer->mutex);
> > +	return 0;  

Best regards,
Hervé