Re: [PATCH] thinkpad_acpi: Add support for keyboard backlight

[Pavel Machek <pavel@ucw.cz>]

On Wed 2016-01-13 20:07:36, Pavel Machek wrote:
> On Wed 2016-01-13 09:54:55, Pali Rohár wrote:
> > On Tuesday 12 January 2016 22:58:04 Pavel Machek wrote:
> > > Hi!
> > > 

> > > Next question is.. apparently there are some keyboards that have
> > > per-key RGB backlight... but maybe we can just call that "weird
> > > enough" and ignore...
> > 
> > First we need to defines stable kernel ABI for keyboard backlight. And I
> > suggest to use existing convention used by upower/console-kit and other
> > userspace apps...
> 
> Hmm... I'm not sure that can be done. What were the masks used by
> upower again? Will upower write to all 6 leds if we present them?

Got it...

It has function up_kbd_backlight_find() which do:

        /* find a led device that is a keyboard device */
	        while ((filename = g_dir_read_name (dir)) != NULL) {
		                if (g_strstr_len (filename, -1, "kbd_backlight") != NULL) {
		                        dir_path = g_build_filename ("/sys/class/leds",
		                                                    filename,
								    	        NULL);
		                        break;
								
That suggests that it stops at the first matching device. Adding new
"virtual" led controlling 6 physical leds would be ugly. So... new
interface should be done.

								Pavel
-- 
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