Re: [patch] collie: enable frontlight

[Pavel Machek <pavel@ucw.cz>]

Hi!

> Pavel Machek <pavel@ucw.cz> wrote:
> >
> > +static spinlock_t fl_lock = SPIN_LOCK_UNLOCKED;
> > +
> > +#define LCM_ALC_EN	0x8000
> > +
> > +void frontlight_set(struct locomo *lchip, int duty, int vr, int bpwf)
> > +{
> > +	unsigned long flags;
> > +
> > +	spin_lock_irqsave(&fl_lock, flags);
> > +	locomo_writel(bpwf, lchip->base + LOCOMO_FRONTLIGHT + LOCOMO_ALS);
> > +	udelay(100);
> > +	locomo_writel(duty, lchip->base + LOCOMO_FRONTLIGHT + LOCOMO_ALD);
> > +	locomo_writel(bpwf | LCM_ALC_EN, lchip->base + LOCOMO_FRONTLIGHT + LOCOMO_ALS);
> > +	spin_unlock_irqrestore(&fl_lock, flags);
> > +}
> 
> ick, a 100 microsecond glitch, quite unnecessary.  Why not use a semaphore
> here, if any locking is actually needed?  (It's called from device probe -
> there's higher-level serialisation, no?)

Oops, I see; I invented my own lock when I should have used
lchip->lock. Fixed locally, I'll push it up eventually.

							Pavel
-- 
Thanks, Sharp!
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/