Bug 77311

Summary:	samsung_laptop + EFI
Product:	Drivers	Reporter:	Alexander Menzhinsky (amenzhinsky)
Component:	Platform_x86	Assignee:	drivers_platform_x86 (drivers_platform_x86)
Status:	NEW ---
Severity:	normal	CC:	matt, rheluani
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	3.15.0-rc8-gfad01e8	Subsystem:
Regression:	No	Bisected commit-id:

Description Alexander Menzhinsky 2014-06-04 08:56:53 UTC

There was an issue that the samsung_laptop module bricked laptops for some reason when the system booted in the efi mode and it was fixed not to load the module at all.

https://github.com/torvalds/linux/commit/e0094244e41c4d0c7ad69920681972fc45d8ce34

It seems nothing has done since and lucky samsung latop owners still can't get some functionality working.

Comment 1 Matt Fleming 2014-09-19 09:47:09 UTC

All the required functionality should be available via ACPI. The reason it was disabled on EFI is documented in the commit message,

"So disable it if booting from EFI since this driver relies on grovelling around in the BIOS memory map which isn't going to work."

What functionality are you missing?

Comment 2 Reimundo Heluani 2014-12-30 10:42:46 UTC

(In reply to Matt Fleming from comment #1)
> All the required functionality should be available via ACPI. The reason it
> was disabled on EFI is documented in the commit message,
> 
> "So disable it if booting from EFI since this driver relies on grovelling
> around in the BIOS memory map which isn't going to work."
> 
> What functionality are you missing?

I myself on a 530U3C booting in UEFI mode a kernel 3.14.14 don't have functioning Fn+F11 (fan speed control) and Fn+F12 (rfkill) which where provided by the samsung-laptop module in legacy mode.  

Less directly related: there is no "device" directory under /sys/class/hwmon/hwmon0/ and the values in the likes of /sys/bus/acpi/drivers/fan/*/thermal_cooling/cur_state show nothing relevant. In short I do not know how to control Fan speed on this machine. 

Perhaps even less directly related: I suspect that related to the faulty BIOS on these Samsungs is that none of my LEDs do work, not even the one that should be lit when connected to a power outlet. I do not have windows to reflash and try with a fresh BIOS.

Comment 3 Reimundo Heluani 2014-12-30 12:20:10 UTC

(In reply to Reimundo Heluani from comment #2)

> I myself on a 530U3C booting in UEFI mode a kernel 3.14.14 don't have
> functioning Fn+F11 (fan speed control) and Fn+F12 (rfkill) which where
> provided by the samsung-laptop module in legacy mode.  

Disregard this comment, the keys themselves do work as seen by acpi_listen, what doesn't work is the driver to control the FAN nor the rfkill. But this is most probably due to a faulty BIOS: all Fan devices in the DSDT are given by something like 

Device (FAN0)
        {
            Name (_HID, EisaId ("PNP0C0B"))  //  Fan 0
            Name (_UID, Zero)  // _UID: Unique ID
            Name (_PR0, Package (0x01)  // _PR0: Power Resources for D0
            {
                FN00
            })
        }

        PowerResource (FN01, 0x00, 0x0000)
        {
            Method (_STA, 0, Serialized)  // _STA: Status
            {
                Return (VFN1)
            }

            Method (_ON, 0, Serialized)  // _ON_: Power On
            {
                Store (One, VFN1)
            }

            Method (_OFF, 0, Serialized)  // _OFF: Power Off
            {
                Store (Zero, VFN1)
            }
        }