Re: [PATCH] dell-laptop: use dedicated sysfs file for ALS

[Darren Hart <dvhart@infradead.org>]

On Wed, Jan 14, 2015 at 03:05:57PM +0100, Gabriele Mazzotta wrote:
> The ambient light sensor doesn't act like an input trigger, so it has
> to be kept separate. The sensor readings are used to determine whether
> the conditions to change the keyboard illumination are satisfied or
> not the moment an input trigger is used. Ambient light changes alone
> can't change the keyboard backlight illumination and don't restart the
> timer.
> 
> Signed-off-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
> ---

...

> +static ssize_t kbd_led_als_enabled_store(struct device *dev,
> +					 struct device_attribute *attr,
> +					 const char *buf, size_t count)
> +{
> +	struct kbd_state new_state;
> +	struct kbd_state state;
> +	bool triggers_enabled = false;
> +	int enable;
> +	int ret;
> +
> +	if (!kbd_als_supported) {
> +		pr_warn("ALS mode is not supported\n");
> +		return -ENODEV;


Will this sysfs file exist if !kbd_als_supported? If so, can we prevent that?

...

Generally speaking, there is a lot more change here than I would like for an
RC5. I'm going to have to consider this one carefully. If we can't come up with
a simpler fix for this RC series, we may have to revert the previous patch and
target this for 3.20.

-- 
Darren Hart
Intel Open Source Technology Center