Keyboard backlight not working on my NP900X5N laptop <previous not accepted due to HTML encoding>

[Jan Vlietland]

Hi all,

Greg K-H suggested to mail you guys.

I installed Linux 4.20.0-rc7 (downloaded, compiled and installed) on a Samsung NP900X5N laptop and have noticed 3 bugs. 2 of them I found in Bugzilla and replied on them (i915 and Nouveau issues). I am currently discussing them with an intel engineer.

On other bug I haven't found so therefore a mail directly to you guys as maintainers.

On my other machine, a Samsung NP900X4D (just bought it in the USA, 2017 model), the samsung-laptop.ko module is enabling the use of the keyboard backlight keys.

It is not working on my new machine NP900X5N. My samsung-laptop.ko driver isn't loading. If I try to load it manually it complains about 'no such device".

My Linux kernel is working in CSM mode. The module is still not loaded.

As it is weekend I did some more reading and debugging of the module. To my understanding the module checks the model and type of the laptop. The known models and types are stored in the struct:

static struct dmi_system_id __initdata samsung_dmi_table[]

I wondr if the NP900X5N notebook is included in this list.

With dmidecode -t chassis it shows:
Getting SMBIOS data from sysfs.
SMBIOS 3.0.0 present.

Handle 0x0003, DMI type 3, 22 bytes
Chassis Information
        Manufacturer: SAMSUNG ELECTRONICS CO., LTD.
        Type: Notebook
        Lock: Not Present
        Version: N/A
        Serial Number: 0F4C91CJ900346
        Asset Tag: No Asset Tag
        Boot-up State: Safe
        Power Supply State: Safe
        Thermal State: Other
        Security Status: None
        OEM Information: 0x00000000
        Height: Unspecified
        Number Of Power Cords: 1
        Contained Elements: 0
        SKU Number: Chassis

If I use the -u flag. The notebook value is 0x0A, not 0x10!!!

Could that be the reason for not loading?

		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR,
					"SAMSUNG ELECTRONICS CO., LTD."),
			DMI_MATCH(DMI_CHASSIS_TYPE, "10"), /* Notebook */
		},

Maybe another reason could that that either the i915 and Nouveau modules 
are not working well. I get black screens with the i915 and MMIO faults 
with the nouveau driver. That is another issue that I need to tackle.

Oh happy new year :-)

--

Met vriendelijke groet,

*dr. Jan Vlietland*, namens

spin-off

Nederlands Instituut voor de Software Industrie

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