Re: [PATCH] Enable Dell All-In-One volume up/down keys

From: Dmitry Torokhov
Date: Thu Feb 17 2011 - 12:22:18 EST


On Thu, Feb 17, 2011 at 11:10:11AM +0000, Colin Ian King wrote:
> Thanks for your feedback Dmitry,
>
> On Wed, 2011-02-16 at 23:52 -0800, Dmitry Torokhov wrote:
> > Hi Colin,
> >
> > On Mon, Feb 14, 2011 at 01:02:04PM +0000, Colin King wrote:
> > > From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> > >
> > > Enable volume up and down hotkeys on WMI events
> > > GUID 284A0E6B-380E-472A-921F-E52786257FB and
> > > GUID 02314822-307C-4F66-bf0E-48AEAEB26CC8.
> > >
> > > Also works around a firmware bug where the _WED method
> > > should return an integer containing the key code and in fact
> > > the method returns the key code in element zero of a buffer.
> > >
> > > BugLink: http://bugs.launchpad.net/bugs/701530
> > > BugLink: http://bugs.launchpad.net/bugs/676997
> >
> > Looks generally good, one question though - should't it be part of
> > dell-wmi driver?
>
> Good question. A couple of points:
>
> 1. The Dell All-In-One WMI hotkey mechanism is a little different from
> the
> normal Dell WMI hotkey mechanism, so I didn't really want to clutter up
> the
> Dell WMI driver with exceptions for these particular GUIDs and notifier
> IDs.
>
> 2. These keys appear on a very limited subset of Dell machines, so
> keeping
> this code out of the Dell WMI driver for the majority of Dell machines
> will
> keep the original Dell WMI driver smaller.
>
> 3. I expect further additions in functionality for these machines, which
> makes sense to keep it specific to this limited All-In-One driver.
>
> As it stands, this All-In-One interface has already been implemented by
> two different BIOS vendors and already there are two different
> implementations. I'd like to keep this all in one specific driver for
> this class of machine if possible.

OK, fair enough.

> From 7a4c2b706317df9be5b7514934e87412fa64eaf4 Mon Sep 17 00:00:00 2001
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> Date: Thu, 17 Feb 2011 10:49:30 +0000
> Subject: [PATCH] Enable Dell All-In-One volume up/down keys
>
> Enable volume up and down hotkeys on WMI events
> GUID 284A0E6B-380E-472A-921F-E52786257FB4 and
> GUID 02314822-307C-4F66-bf0E-48AEAEB26CC8.
>
> Also works around a firmware bug where the _WED method
> should return an integer containing the key code and in fact
> the method returns the key code in element zero of a buffer.
>
> BugLink: http://bugs.launchpad.net/bugs/701530
> BugLink: http://bugs.launchpad.net/bugs/676997
>
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>

Looks much better, but I just noticed that we are missing calls to
sparse_keymap_free(dell_wmi_aio_input_dev) in both probe error handling
path and in remove method (they shoudl be called before unregistering
the device).

Also, can we have probe routine more streamlined, like this:

static int __init dell_wmi_aio_init(void)
{
int err;
char *guid;

guid = dell_wmi_aio_find();
if (!guid) {
pr_error("No known WMI GUID found\n");
return -ENXIO;
}

err = dell_wmi_aio_input_setup();
if (err)
return err;

err = wmi_install_notify_handler(guid, dell_wmi_aio_notify, NULL);
if (err) {
pr_err("Unable to register notify handler - %d\n", err);
sparse_keymap_free(dell_wmi_aio_input_dev);
input_unregister_device(dell_wmi_aio_input_dev);
return err;
}

return 0;
}

Thanks.

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