0

I have an Acer Aspire ES1-531-P8JN. It has the Intel N3700 CPU with integrated graphics. I have the problem that the video driver i915 does not seem to work in Debian Jessie 8.3.0, even though it does work on (L)Ubuntu 15.10. I am concerned about this, because I'd like the program xbacklight to work on Debian, too, because I actually prefer Debian over Ubuntu, but had to switch to Lubuntu, because my eyes got really strained.

Here is what I get for sudo lshw -c video in Debian:

  *-display UNCLAIMED
       description: VGA compatible controller
       product: Intel Corporation
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 21
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi vga_controller bus_master cap_list
       configuration: latency=0
       resources: memory:90000000-90ffffff memory:80000000-8fffffff ioport:2000(size=64)

And here is what I get in Lubuntu:

  *-display
       description: VGA compatible controller
       product: Intel Corporation
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 21
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi vga_controller bus_master cap_list rom
       configuration: driver=i915 latency=0
       resources: irq:312 memory:90000000-90ffffff memory:80000000-8fffffff ioport:2000(size=64)

lsmod | grep i915 in Debian gives me:

i915                           837175  0 
drm_kms_helper         49210        1   i915
drm                             249955  2   i915,drm_kms_helper
i2c_algo_bit                12751       1   i915
video                            18096      2   i915,acer_wmi
button                      12944       1   i915
i2c_core                    46012       7   drm,i915,i2c_hid,drm_kms_helper,i2c_algo_bit,v4l2_common,videodev

And in Lubuntu:

i915                       1130496     4
i2c_algo_bit                16384       1    i915
drm_kms_helper          126976      1    i915
drm                             356352      5   i915,drm_kms_helper
video                           ls 36864    2   i915,acer_wmi

Also there is no entry in /sys/class/backlight in Debian, while in Lubuntu I have intel_backlight. I read somewhere that when there is no entry in /sys/class/backlight it means that the Linux kernel thinks that the display is a very old one where there is a physical brightness switch. But I don't think the kernel that Debian and Ubuntu use are that different.

Please help me get xbacklight to work on Debian. Thanks!

Edit: I add the error messages in dmesg: Lubuntu:

[    0.182944] ACPI Error: No handler for Region [RAM_] (ffff88017b4b8558) [EmbeddedControl] (20150619/evregion-163)
[    0.182955] ACPI Error: Region EmbeddedControl (ID=3) has no handler (20150619/exfldio-297)
[    0.182966] ACPI Error: Method parse/execution failed [\_SB_.PCI0.LPCB.EC0_._REG] (Node ffff88017b4b9208), AE_NOT_EXIST (20150619/psparse-536)
[    0.183081] ACPI Error: No handler for Region [RAM_] (ffff88017b4b8558) [EmbeddedControl] (20150619/evregion-163)
[    0.183089] ACPI Error: Region EmbeddedControl (ID=3) has no handler (20150619/exfldio-297)
[    0.183097] ACPI Error: Method parse/execution failed [\_SB_.PCI0.LPCB.EC0_._REG] (Node ffff88017b4b9208), AE_NOT_EXIST (20150619/psparse-536)
[    0.243103] acpi PNP0A08:00: _OSC failed (AE_ERROR); disabling ASPM
[    1.971340] [drm:valleyview_update_wm [i915]] *ERROR* timed out waiting for Punit DDR DVFS request
[    2.356840] [drm:valleyview_update_wm [i915]] *ERROR* timed out waiting for Punit DDR DVFS request
[    3.270826] [drm:valleyview_update_wm [i915]] *ERROR* timed out waiting for Punit DDR DVFS request
[   16.051457] EXT4-fs (sda5): re-mounted. Opts: errors=remount-ro
[  110.693938] [drm:valleyview_update_wm [i915]] *ERROR* timed out waiting for Punit DDR DVFS request
[  116.909911] [drm:valleyview_update_wm [i915]] *ERROR* timed out waiting for Punit DDR DVFS request
[  118.610041] [drm:valleyview_update_wm [i915]] *ERROR* timed out waiting for Punit DDR DVFS request
[  221.721939] [drm:valleyview_update_wm [i915]] *ERROR* timed out waiting for Punit DDR DVFS request
[  223.091774] [drm:valleyview_update_wm [i915]] *ERROR* timed out waiting for Punit DDR DVFS request

Debian:

[    0.200280] ACPI Error: No handler for Region [RAM_] (ffff88017f056938) [EmbeddedControl] (20140424/evregion-163)
[    0.200290] ACPI Error: Region EmbeddedControl (ID=3) has no handler (20140424/exfldio-297)
[    0.200300] ACPI Error: Method parse/execution failed [\_SB_.PCI0.LPCB.EC0_._REG] (Node ffff88017f057f18), AE_NOT_EXIST (20140424/psparse-536)
[    0.200412] ACPI Error: No handler for Region [RAM_] (ffff88017f056938) [EmbeddedControl] (20140424/evregion-163)
[    0.200419] ACPI Error: Region EmbeddedControl (ID=3) has no handler (20140424/exfldio-297)
[    0.200426] ACPI Error: Method parse/execution failed [\_SB_.PCI0.LPCB.EC0_._REG] (Node ffff88017f057f18), AE_NOT_EXIST (20140424/psparse-536)
[    0.389651] acpi PNP0A08:00: _OSC failed (AE_ERROR); disabling ASPM
[    8.578880] EXT4-fs (dm-0): re-mounted. Opts: errors=remount-ro
[    9.899828] usb 1-5.1: Direct firmware load failed with error -2
[    9.902636] ath3k: probe of 1-5.1:1.0 failed with error -12

According to this site, not having any entries in /sys/class/backlight might also mean problems with the ACPI backlight driver. There were some error messages regarding ACPI in dmesg, but unfortunately not only in Debian, but also in Ubuntu. In Ubuntu backlight control works, though.

Edit2: The kernel version of Debian 8.3.0 is 3.16.0-4-amd64, while the kernel of Lubuntu 15.10 is of a newer version 4.2.0-27-generic. I wonder if that makes a difference...

  • Check with dmesg -H for errors (e.g. missing firmware). Note that debian doesn't install by default non-free firmware. – Giacomo Catenazzi Feb 16 '16 at 20:39
  • Check that you have firmware-misc-nonfree installed. dpkg -l firmware-misc-nonfree. The kernel version is not that likely to make a difference, but you can certainly try the 4.3 kernel jessie backport if you want, in parallel with the default 3.16 kernel. – Faheem Mitha Feb 16 '16 at 22:25
  • @FaheemMitha: firmware-misc-nonfree was already installed, because I deliberately installed from the non-free firmware version. – mkdrive2 Feb 16 '16 at 22:56
1

I installed the precompiled 4.3.0-0.bpo.1-amd64 kernel following this guide, and immediately an entry intel_backlight appeared in /sys/class/backlight, and the program xbacklight worked, too.

(It seems like the hardware was so new that it was not supported by the old kernel. I just got this notebook.)

Now, I am kind of excited that this works, since it was the main reason why I could not work with Debian, despite everything that I dislike about Ubuntu, and everything I like about Debian. But the kernel upgrade already shows some side effects. iceweasel crashes a lot now. And that is one of the few programs I tested until now.

So, even though it is not a perfect solution, it is good enough for me.

  • 4.4. is also available, in Debian experimental. This may also be worth trying. It helped another poster recently. Link available on request. You could also try an updated iceweasel. – Faheem Mitha Feb 17 '16 at 8:20
  • @FaheemMitha: How do I update iceweasel? It is already the newest version... – mkdrive2 Feb 17 '16 at 9:32
  • 38.6.1esr-1~deb8u1 is the latest iceweasel version on jessie. You could backport a version from unstable or experimental. But first try wiki.debian.org/…. Also, try 4.4. That may work better. – Faheem Mitha Feb 17 '16 at 10:51

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.