[PATCH 1/2] leds: Add generic support for memory mapped LEDs
Pawel Moll
pawel.moll at arm.com
Mon Nov 5 07:55:59 EST 2012
On Mon, 2012-11-05 at 09:39 +0000, Jon Medhurst (Tixy) wrote:
> > +static void mmio_led_brightness_set(struct led_classdev *cdev,
> > + enum led_brightness brightness)
> > +{
> > + struct mmio_led *led = container_of(cdev, struct mmio_led, cdev);
> > + unsigned long uninitialized_var(flags);
>
> uninitialized_var seems to be a bit contentious, Linus Torvalds had a
> recent complaint about it which prompted Ingo to post a patch proposing
> to removing it: https://patchwork.kernel.org/patch/1655621/ So perhaps
> best to avoid using it ;-).
>
> In this case, you could possibly keep gcc quite with something like:
>
> spinlock_t *lock = led->lock;
>
> and then use the local variable 'lock' everywhere instead of led->lock.
> Or just keep it simple an initialise flags to 0 instead.
Yeah, = 0 will do...
> > + if (!pdata)
> > + return -EINVAL;
> > +
> > + if (pdata->reg_size != 8 && pdata->reg_size != 16 &&
> > + pdata->reg_size != 32)
> > + return -EFAULT;
>
> Is EFAULT appropriate here? Why not EINVAL?
Hm. To distinguish it from !pdata case I guess (and a 13 bit wide
transaction sounds like a fault to me ;-), but I can be persuaded
otherwise without much effort...
Thanks!
Paweł
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