Re: [RFC PATCHv2 4/5] hwmon: lis3: Remove the referencies to theglobal variable in core driver

[Ilkka Koskinen]

Hi,

Thanks for the comments!

On Tue, 5 Apr 2011, ext Thadeu Lima de Souza Cascardo wrote:
> On Tue, Apr 05, 2011 at 05:45:13PM +0300, Ilkka Koskinen wrote:
> > Signed-off-by: Ilkka Koskinen <ilkka.koskinen@xxxxxxxxx>
> > ---
> >  drivers/misc/lis3lv02d/lis3lv02d.c |  237 ++++++++++++++++++++----------------
> >  drivers/misc/lis3lv02d/lis3lv02d.h |    3 +
> >  2 files changed, 135 insertions(+), 105 deletions(-)

> > @@ -980,14 +1003,18 @@ int lis3lv02d_init_device(struct lis3lv02d *lis3)
> >  				thread_fn,
> >  				IRQF_TRIGGER_RISING | IRQF_ONESHOT |
> >  				irq_flags,
> > -				DRIVER_NAME, &lis3_dev);
> > +				DRIVER_NAME, lis3);
> >
> >  	if (err < 0) {
> >  		pr_err("Cannot get IRQ\n");
> >  		goto out;
> >  	}
> >
> > -	if (misc_register(&lis3lv02d_misc_device))
> > +	lis3->miscdev.minor	= MISC_DYNAMIC_MINOR;
> > +	lis3->miscdev.name	= "freefall";
> > +	lis3->miscdev.fops	= &lis3lv02d_misc_fops;
> > +
> > +	if (misc_register(&lis3->miscdev))
> >  		pr_err("misc_register failed\n");
>
> You should not use miscdevice in case there will be multiple devices.
> First, it will fail. There cannot be more than one device with the same
> name. Second, current dynamic minor devices is restricted to 64 devices.
> Since this is reserved to one-shot devices, freefall was OK as a misc
> device until you fixed it to allow multiple freefall devices.  :-)

Ah, true :)

> So, I'd recommend switching to a new device class, and have freefall0,
> freefall1, etc.

I wonder if introducing a new class makes sense. I mean, I can figure out 
use cases for several accelerometers but for several free fall sensors? :/

Would it be better to add a mechanism to tell to the core module if the 
particular device is used for free fall detection or not?

Cheers, Ilkka

> Anyway, good job on this.
>
> Regards,
> Cascardo.

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