Re: [PATCH 01/12] thinkpad_ec: New driver for ThinkPad embedded controller access

From: Shem Multinymous
Date: Tue Aug 08 2006 - 05:21:37 EST

On 8/8/06, Pavel Machek <pavel@xxxxxxx> wrote:
Okay... but do we really need try_lock variant?

We need a nonlocking, nonsleeping variant to do the query in the timer
function (softirq context).

but what is try_lock semantics when taking multiple locks...?

Currently, the same as the undelying down_trylock().

> >> + if (!check_dmi_for_ec()) {
> >> + printk(KERN_ERR "thinkpad_ec: no ThinkPad embedded
> >controller!\n");
> >> + return -ENODEV;
> >
> >KERN_ERR is little strong here, no?
> Not sure what's the right one. The user tried to load a module and the
> module can't do that; I saw some drivers use KERN_ERR some
> KERN_WARNING in similar cases. Is there some guideline on choosing
> printk levels?

Well, this will also trigger for thinkpad module compiled into kernel,

OK, I'm changing the DMI failure to KERN_WARNING. Subsequent hardware
checks remains KERN_ERR, since failing those after passing the DMI
check really is abnormal (and indicative of danger).

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