Bug 1045872

Summary: Can't load samsung-laptop module on Samsung NP900X3C
Product: [Fedora] Fedora Reporter: Rui Miguel Seabra <rms>
Component: kernelAssignee: Kernel Maintainer List <kernel-maint>
Status: CLOSED CANTFIX QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: low Docs Contact:
Priority: unspecified    
Version: 20CC: gansalmon, itamar, jonathan, kernel-maint, madhu.chinakonda, michele, rms
Target Milestone: ---   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2014-01-02 08:16:11 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Attachments:
Description Flags
dmesg from boot
none
sudo dmidecode > demidecode.txt none

Description Rui Miguel Seabra 2013-12-22 18:00:59 UTC
Created attachment 840380 [details]
dmesg from boot

Description of problem:

[rms@roque ~]$ sudo modprobe samsung-laptop
modprobe: ERROR: could not insert 'samsung_laptop': No such device


Version-Release number of selected component (if applicable):

[rms@roque ~]$ rpm -q kernel
kernel-3.11.6-301.fc20.x86_64
kernel-3.11.10-301.fc20.x86_64
[rms@roque ~]$ uname -a
Linux roque 3.11.10-301.fc20.x86_64 #1 SMP Thu Dec 5 14:01:17 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux


Actual results:

Strange failure, what device is it looking for? Why is it not there?

samsung directory is not present:

[rms@roque ~]$ ls -laF /sys/devices/platform/
total 0
drwxr-xr-x. 12 root root    0 Dec 22 17:38 ./
drwxr-xr-x. 14 root root    0 Dec 22 17:38 ../
drwxr-xr-x.  3 root root    0 Dec 22 17:38 alarmtimer/
drwxr-xr-x.  4 root root    0 Dec 22 17:38 coretemp.0/
drwxr-xr-x.  3 root root    0 Dec 22 17:38 efifb.0/
drwxr-xr-x.  4 root root    0 Dec 22 17:38 Fixed MDIO bus.0/
drwxr-xr-x.  5 root root    0 Dec 22 17:38 i8042/
drwxr-xr-x.  3 root root    0 Dec 22 17:38 microcode/
drwxr-xr-x.  3 root root    0 Dec 22 17:38 pcspkr/
drwxr-xr-x.  2 root root    0 Dec 22 17:49 power/
drwxr-xr-x.  3 root root    0 Dec 22 17:38 regulatory.0/
drwxr-xr-x.  4 root root    0 Dec 22 17:38 serial8250/
-rw-r--r--.  1 root root 4096 Dec 22 17:38 uevent
[rms@roque ~]$ 


Expected results:

Loaded module, /sys/devices/platform/samsung/... available exposing access to features like controlling keyboard brightness and fan

Comment 1 Rui Miguel Seabra 2014-01-01 19:00:03 UTC
Still happens with Linux 3.12:

[rms@roque f]$ sudo modprobe samsung-laptop
[sudo] password for rms: 
modprobe: ERROR: could not insert 'samsung_laptop': No such device
[rms@roque f]$ uname -a
Linux roque 3.12.5-302.fc20.x86_64 #1 SMP Tue Dec 17 20:42:32 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
[rms@roque f]$

Comment 2 Michele Baldessari 2014-01-01 21:00:06 UTC
Hi Rui,

the driver returns ENODEV when loaded under the following conditions:
- Booted from EFI
- Dmi fields not recognized

Can you upload the output of dmidecode to this case please?

Thanks,
Michele

Comment 3 Rui Miguel Seabra 2014-01-01 21:05:16 UTC
Created attachment 844263 [details]
sudo dmidecode > demidecode.txt

Comment 4 Rui Miguel Seabra 2014-01-01 21:06:35 UTC
I guess I'm screwed as I'm booting under EFI. Will I have to find out how to revert back to legacy BIOS or is it safer to reinstall?

In any case, I have attached dmidecode's output.

Comment 5 Michele Baldessari 2014-01-02 07:04:31 UTC
Hi Rui,

the reason it is disabled with EFI is the following:
commit e0094244e41c4d0c7ad69920681972fc45d8ce34
Author: Matt Fleming <matt.fleming>
Date:   Thu Jan 3 09:02:37 2013 +0000

    samsung-laptop: Disable on EFI hardware
    
    It has been reported that running this driver on some Samsung laptops
    with EFI can cause those machines to become bricked as detailed in the
    following report,
    
        https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557
    
    There have also been reports of this driver causing Machine Check
    Exceptions on recent EFI-enabled Samsung laptops,
    
        https://bugzilla.kernel.org/show_bug.cgi?id=47121
    
    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.


The DMI info would match, so we can definitely confirm that it is the EFI thing.

I have no idea what's faster (reinstall vs. tweaking around) sorry

Comment 6 Rui Miguel Seabra 2014-01-02 08:16:11 UTC
OH, ok, I see. I read about this a long while ago, I expected this would have been fixed in the meanwhile and not an issue anymore.

I will reinstall with legacy boot then, thanks!