Re: [PATCH] platform/x86: lg-laptop: Support for battery charge limit on newer models

[Matan Ziv-Av <matan@svgalib.org>]

On Wed, 18 Aug 2021, Hans de Goede wrote:

> Hi,
> 
> On 8/14/21 12:11 AM, Matan Ziv-Av wrote:
> > 
> > Add support for the difference between various models:
> > 
> > - Use dmi to detect laptop model.
> > - 2019 and newer models use _wmbb method to set battery charge limit.
> > 
> > Signed-off-by: Matan Ziv-Av <matan@svgalib.org>
> 
> Thank you for the patch, some small comments inline.
> 
> 
> Please drop the ! from the if condition and swap the 2 branches.

Fixed.

> > +	product = dmi_get_system_info(DMI_PRODUCT_NAME);
> > +	if (strlen(product) > 4)
> > +		switch (product[4]) {
> > +		case '5':
> > +		case '6':
> > +			year = 2016;
> > +			break;
> > +		case '7':
> > +			year = 2017;
> > +			break;
> > +		case '8':
> > +			year = 2018;
> > +			break;
> > +		case '9':
> > +			year = 2019;
> > +			break;
> > +		case '0':
> > +			if (strlen(product) > 5)
> > +				switch (product[5]) {
> > +				case 'N':
> > +					year = 2020;
> > +					break;
> > +				case 'P':
> > +					year = 2021;
> > +					break;
> > +				default:
> > +					year = 2022;
> > +				}
> > +			break;
> > +		default:
> > +			year = 2019;
> > +		}
> > +	pr_info("product: %s  year: %d\n", product, year);
> > +
> > +	if (year >= 2019)
> > +		battery_limit_use_wmbb = 1;
> 
> This does not feel very robust how about doing a strstr for "201" and if that
> fails for "202" to find the year ?

Unfortunately, this is not so simple.

Some example model numbers:

15Z960-A.AA75U1
15Z980-R.AAS9U1
14T990-U.AAS8U1
17Z90P-K.AAB8U1

First two digits represent screen size. Third letter device type. Fifth 
digit is the last digit of the model year (up to 2021, where it is 0 and 
the sixth letter indicates the model year).

> Regards,
> 
> Hans
> 
> p.s.
> 
> While reviewing this I also took a quick look at the existing lg-laptop.c
> and the wmi_keymap stood out to me, specifically:
> 
>         {KE_KEY, 0x74, {KEY_F13} },      /* Touchpad toggle (F5) */
> 
> If that key just sends this event and does not actually change the
> touchpad settings, IOW userspace is supposed to react this (e.g.
> filter out touchpad events in software after the toggle), then the
> correct key to send here would be KEY_F21, this has been the standard
> key-code to send for this for a while now and GNOME and KDE will
> automatically do the right thing when sending that, including a
> nice on-screen-display (OSD)notifcation (like when changing the volume)
> indicating the new (software) state (on or off) of the touchpad.
> 
> If the hw does actually handle the touchpad on/off itself
> (I see there also is a touchpad-led?) then the right thing to do
> would be to send f22 (Touchpad toggle off-to-on) and f23
> (Touchpad toggle on-to-off). This assumes that you can figure
> out the new touchpad state. When receiving f22 / f23 GNOME will
> display the OSD without making any other settings changes.
>
> Also see: /lib/udev/hwdb.d/60-keyboard.hwdb
> 
> 
>         {KE_KEY, 0x10000000, {KEY_F16} },/* Keyboard backlight (F8) - pressing
>                                           * this key both sends an event and
>                                           * changes backlight level.
>                                           */
> 
> If this hotkey changes the kbd-backlight level "in hardware"
> then it should not send a key-press instead you should specify
> 
> led_classdev.flags = LED_BRIGHT_HW_CHANGED
> 
> For the kbd-backlight led_classdev and then call:
> 
> 	led_classdev_notify_brightness_hw_changed(&kbd_backlight, new_backlight_level);
> 
> When receiving the event. upower will pick the event send by this up
> and then notify interested parties such as e.g. gnome-settings-daemon
> which will then show a nice OSD with the new backlight level similar
> to how it is done for e.g. volume controls.
> 
> 
> If you can also send patches to change these 2 things, so that lg-laptop
> conforms with the standard userspace APIs used for this that would be great.

I sent patches for this (in a separate thread). But in my testing, this 
does not happen automatically and I did not find yet how to configure 
udev/upower/kde to display this notification.




-- 
Matan.