Re: [RFC PATCH 1/2] Input: add msi-wmi driver to support hotkeys in MSI Windtop AE1900-WT

[Anisse Astier <anisse@astier.eu>]

On Wed, 2 Dec 2009 19:11:28 -0800, Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote :

> Hi Anisse,
> 
> On Wed, Dec 02, 2009 at 07:26:03PM +0100, Anisse Astier wrote:
> > +
> > +	if (jiffies_to_msecs(get_jiffies_64() -
> > msi_wmi_time_last_press)
> > +			> pression_timeout) {
> 
> Why don't you use time_after() instead of manual computation?
> 
> Also, what is the point of this? If you are trying to debounce the
> buttons this will not quite work. To do debouncing properly you need
> to store the value you just read and fire up a timer. When timer
> fires - that's the stable value.

Indeed, the point is to debounce the keys. I guess I’ll just use the 
debounce mecanism in use in the gpio_keys driver.
But why use a timer instead of a delayed workqueue? Do we need the precison
of a timer for a simple debounce?

> > +		printk(KERN_DEBUG
> > +				"MSI WMI: event correctly
> > received: %llu\n",
> > +				obj->integer.value);
> 
> This is way too noisy for the mainline kernel, pr_debug() perhaps?
Sure.

> > +	msi_wmi_input_setup();
> 
> 
> You need to handle errors returned by msi_wmi_input_setup() as well.

Yes, I reworked the init in the second patch, I'll put the clean init in
the first one for v2.

> > +MODULE_PARM_DESC(pression_timeout,
> > +		 "How much time interrupts are ignored between
> > each pression");
> 
> This is not the best option name:
> 
> MODULE_PARM_DESC(debounce_interval,
> 		 "Controls how long driver will wait for button to
> debounce");
> 

Thanks a lot for your comments.

Regards,

Anisse
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