linux-kernel - Re: [PATCH 1/2] platform/x86: asus-wmi: Call new led hw

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Date:   Mon, 4 Jun 2018 19:17:51 -0700
From:   Darren Hart <dvhart@...radead.org>
To:     Chris Chiu <chiu@...lessm.com>
Cc:     corentin.chary@...il.com, andy.shevchenko@...il.com,
        linux-kernel@...r.kernel.org, platform-driver-x86@...r.kernel.org,
        acpi4asus-user@...ts.sourceforge.net, hdegoede@...hat.com,
        linux@...lessm.com
Subject: Re: [PATCH 1/2] platform/x86: asus-wmi: Call new led hw_changed API
 on kbd brightness change

On Mon, Jun 04, 2018 at 08:32:37PM +0800, Chris Chiu wrote:
> Make asus-wmi notify on hotkey kbd brightness changes, listen for
> brightness events and update the brightness directly in the driver.
> For this purpose, bound check on brightness in kbd_led_set must be
> based on the same data type to prevent illegal value been set.
> 
> Update the brightness by led_classdev_notify_brightness_hw_changed.
> This will allow userspace to monitor (poll) for brightness changes
> on the LED without reporting via input keymapping.
> 
> Signed-off-by: Chris Chiu <chiu@...lessm.com>
> ---
>  drivers/platform/x86/asus-nb-wmi.c |  2 --
>  drivers/platform/x86/asus-wmi.c    | 21 +++++++++++++++++++--
>  2 files changed, 19 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/platform/x86/asus-nb-wmi.c b/drivers/platform/x86/asus-nb-wmi.c
> index 136ff2b4cce5..7ce80e4bb5a3 100644
> --- a/drivers/platform/x86/asus-nb-wmi.c
> +++ b/drivers/platform/x86/asus-nb-wmi.c
> @@ -493,8 +493,6 @@ static const struct key_entry asus_nb_wmi_keymap[] = {
>  	{ KE_KEY, 0xA6, { KEY_SWITCHVIDEOMODE } }, /* SDSP CRT + TV + HDMI */
>  	{ KE_KEY, 0xA7, { KEY_SWITCHVIDEOMODE } }, /* SDSP LCD + CRT + TV + HDMI */
>  	{ KE_KEY, 0xB5, { KEY_CALC } },
> -	{ KE_KEY, 0xC4, { KEY_KBDILLUMUP } },
> -	{ KE_KEY, 0xC5, { KEY_KBDILLUMDOWN } },
>  	{ KE_IGNORE, 0xC6, },  /* Ambient Light Sensor notification */
>  	{ KE_END, 0},
>  };
> diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
> index 1f6e68f0b646..b4915b7718c1 100644
> --- a/drivers/platform/x86/asus-wmi.c
> +++ b/drivers/platform/x86/asus-wmi.c
> @@ -460,6 +460,7 @@ static void kbd_led_update(struct work_struct *work)
>  		ctrl_param = 0x80 | (asus->kbd_led_wk & 0x7F);
>  
>  	asus_wmi_set_devstate(ASUS_WMI_DEVID_KBD_BACKLIGHT, ctrl_param, NULL);
> +	led_classdev_notify_brightness_hw_changed(&asus->kbd_led, asus->kbd_led_wk);
>  }
>  
>  static int kbd_led_read(struct asus_wmi *asus, int *level, int *env)
> @@ -497,9 +498,9 @@ static void kbd_led_set(struct led_classdev *led_cdev,
>  
>  	asus = container_of(led_cdev, struct asus_wmi, kbd_led);
>  
> -	if (value > asus->kbd_led.max_brightness)
> +	if ((int)value > (int)asus->kbd_led.max_brightness)
>  		value = asus->kbd_led.max_brightness;
> -	else if (value < 0)
> +	else if ((int)value < 0)
>  		value = 0;
>  
>  	asus->kbd_led_wk = value;
> @@ -656,6 +657,7 @@ static int asus_wmi_led_init(struct asus_wmi *asus)
>  
>  		asus->kbd_led_wk = led_val;
>  		asus->kbd_led.name = "asus::kbd_backlight";
> +		asus->kbd_led.flags = LED_BRIGHT_HW_CHANGED;
>  		asus->kbd_led.brightness_set = kbd_led_set;
>  		asus->kbd_led.brightness_get = kbd_led_get;
>  		asus->kbd_led.max_brightness = 3;
> @@ -1700,6 +1702,13 @@ static int is_display_toggle(int code)
>  	return 0;
>  }
>  
> +static int is_kbd_led_event(int code)
> +{
> +	if (code == NOTIFY_KBD_BRTUP || code == NOTIFY_KBD_BRTDWN)
> +		return 1;
> +	return 0;

I don't think this is worth breaking out into a separate function. This
isn't exactly a hot path, but I don't think this makes the code any more
readable really. The is_display_toggle was comparing 8 values in a
complex logic statement, so we don't need to follow that for something
this simple.

> +}
> +
>  static void asus_wmi_notify(u32 value, void *context)
>  {
>  	struct asus_wmi *asus = context;
> @@ -1745,6 +1754,14 @@ static void asus_wmi_notify(u32 value, void *context)
>  		}
>  	}
>  
> +	if (is_kbd_led_event(code)) {
> +		if (code == NOTIFY_KBD_BRTDWN)

Seems like we could eliminate the extra function and eliminate a level
of indentation by rewriting this as:

	if (code == NOTIFY_KBD_BRTDWN)
		kbd_led_set(&asus->kbd_led, asus->kbd_led_wk - 1);
	else if (code == NOTIFY_KBD_BRTUP)
		kbd_led_set(&asus->kbd_led, asus->kbd_led_wk + 1);
	if (code == NOTIFY_KBD_BRTDWN || NOTIFY_KBD_BRTUP)
		goto exit;

Or, just treat them as separate events:


	if (code == NOTIFY_KBD_BRTDWN) {
		kbd_led_set(&asus->kbd_led, asus->kbd_led_wk - 1);
		goto exit;
	}

	if (code == NOTIFY_KBD_BRTUP) {
		kbd_led_set(&asus->kbd_led, asus->kbd_led_wk + 1);
		goto exit;
	}



>  	if (is_display_toggle(code) &&
>  	    asus->driver->quirks->no_display_toggle)
>  		goto exit;
> -- 
> 2.11.0
> 
> 

-- 
Darren Hart
VMware Open Source Technology Center