unable to adjust screen brightness

juntjoo · 05-01-2017, 04:54 PM

I used to be able to before but not anymore. IDK why. I still have Ubuntu 16.04 as I've always had. I've seen a thread elsewhere discussing this as a result of possibly a recent update but specific hardware so I wouldn't know if it would apply to my situation. I have an Acer Aspire TimelineX Intel icore 5 with integrated graphics "ironlake mobile" if that helps. If you need more info let me know. The brightness is stuck right in the middle which is good for most situations but not if I want to go outside with my laptop. I can change it under settings with the sliding bar but it doesn't do anything. Thanks

hydrurga · 05-01-2017, 05:18 PM

Have you recently updated your kernel? If you don't know, have a look at the last few entries in /var/log/apt/history.log for "linux-image".

Which kernel are you currently running (uname -r)?

juntjoo · 05-01-2017, 05:34 PM

Quote:

Originally Posted by hydrurga

Have you recently updated your kernel? If you don't know, have a look at the last few entries in /var/log/apt/history.log for "linux-image".

Which kernel are you currently running (uname -r)?

well right near the top it says something about "linux image" with some numbers next to it dated feb 21. I'd look further down the page but it keeps freezing whenever I type just a character after ctrl+f rather than waiting for me to finish and hit enter or search. Don't know why. I was going to type Linux image to search for all instances of that on this fairly large file.

I don't know what you mean by "uname -r"

no, I do: 4.4.0-75-generic

Thanks

hydrurga · 05-01-2017, 05:49 PM

Quote:

Originally Posted by juntjoo

well right near the top it says something about "linux image" with some numbers next to it dated feb 21. I'd look further down the page but it keeps freezing whenever I type just a character after ctrl+f rather than waiting for me to finish and hit enter or search. Don't know why. I was going to type Linux image to search for all instances of that on this fairly large file.

I don't know what you mean by "uname -r"

no, I do: 4.4.0-75-generic

Thanks

uname -r is a command you can enter on the command line to show you the currently running kernel version number.

Ok, I'm just going on the theory here that it was a recent kernel update that caused the problem. Your system should still have the previous kernel installed (dpkg -l '*linux-image*' will list the kernels - can you let me know the previously numbered one to 4.4.0-75?). Also, do you know how to change the kernel through the grub menu when you're booting your machine?

Out of interest, which program are you using to view the log that's causing the freezing? That shouldn't be happening.

juntjoo · 05-01-2017, 06:17 PM

Quote:

Originally Posted by hydrurga

uname -r is a command you can enter on the command line to show you the currently running kernel version number.

Ok, I'm just going on the theory here that it was a recent kernel update that caused the problem. Your system should still have the previous kernel installed (dpkg -l '*linux-image*' will list the kernels - can you let me know the previously numbered one to 4.4.0-75?). Also, do you know how to change the kernel through the grub menu when you're booting your machine?

Out of interest, which program are you using to view the log that's causing the freezing? That shouldn't be happening.

Code:

Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name           Version      Architecture Description
+++-==============-============-============-=================================
un  linux-image    <none>       <none>       (no description available)
rc  linux-image-4. 4.4.0-31.50  amd64        Linux kernel image for version 4.
rc  linux-image-4. 4.4.0-47.68  amd64        Linux kernel image for version 4.
rc  linux-image-4. 4.4.0-51.72  amd64        Linux kernel image for version 4.
rc  linux-image-4. 4.4.0-53.74  amd64        Linux kernel image for version 4.
rc  linux-image-4. 4.4.0-57.78  amd64        Linux kernel image for version 4.
rc  linux-image-4. 4.4.0-59.80  amd64        Linux kernel image for version 4.
ii  linux-image-4. 4.4.0-62.83  amd64        Linux kernel image for version 4.
ii  linux-image-4. 4.4.0-63.84  amd64        Linux kernel image for version 4.
ii  linux-image-4. 4.4.0-64.85  amd64        Linux kernel image for version 4.
ii  linux-image-4. 4.4.0-65.86  amd64        Linux kernel image for version 4.
ii  linux-image-4. 4.4.0-66.87  amd64        Linux kernel image for version 4.
ii  linux-image-4. 4.4.0-72.93  amd64        Linux kernel image for version 4.
ii  linux-image-4. 4.4.0-75.96  amd64        Linux kernel image for version 4.
rc  linux-image-ex 4.4.0-31.50  amd64        Linux kernel extra modules for ve
rc  linux-image-ex 4.4.0-47.68  amd64        Linux kernel extra modules for ve
rc  linux-image-ex 4.4.0-51.72  amd64        Linux kernel extra modules for ve
rc  linux-image-ex 4.4.0-53.74  amd64        Linux kernel extra modules for ve
rc  linux-image-ex 4.4.0-57.78  amd64        Linux kernel extra modules for ve
rc  linux-image-ex 4.4.0-59.80  amd64        Linux kernel extra modules for ve
ii  linux-image-ex 4.4.0-62.83  amd64        Linux kernel extra modules for ve
ii  linux-image-ex 4.4.0-63.84  amd64        Linux kernel extra modules for ve
ii  linux-image-ex 4.4.0-64.85  amd64        Linux kernel extra modules for ve
ii  linux-image-ex 4.4.0-65.86  amd64        Linux kernel extra modules for ve
ii  linux-image-ex 4.4.0-66.87  amd64        Linux kernel extra modules for ve
ii  linux-image-ex 4.4.0-72.93  amd64        Linux kernel extra modules for ve
ii  linux-image-ex 4.4.0-75.96  amd64        Linux kernel extra modules for ve
ii  linux-image-ge 4.4.0.75.81  amd64        Generic Linux kernel image

Thanks.

gedit is the program. It eventually recovers itself but takes forever to gather all the data looking for matching characters I guess, so maybe it's because my computer is slow, but it really isn't even though it's like 5 years old. Well, it does great under Linux and Windows 7.

hydrurga · 05-01-2017, 06:26 PM

Thanks, juntjoo.

Right, so at some point you upgraded from 4.4.0-72 to 4.4.0-75.

To find out when that occurred, run grep 'linux-image-4.4.0-75' /var/log/apt/history.log -C5 (this shows the 5 lines either side of the searched for text in the logfile - look at the Start-Date line portion of the relevant text section).

Does this date tie in roughly with the date that you started experiencing the problem?

juntjoo · 05-01-2017, 07:38 PM

Quote:

Originally Posted by hydrurga

Thanks, juntjoo.

Right, so at some point you upgraded from 4.4.0-72 to 4.4.0-75.

To find out when that occurred, run grep 'linux-image-4.4.0-75' /var/log/apt/history.log -C5 (this shows the 5 lines either side of the searched for text in the logfile - look at the Start-Date line portion of the relevant text section).

Does this date tie in roughly with the date that you started experiencing the problem?

Thanks, it says 4-26 so it would be right before I noticed which only happened to be because I decided to use my laptop outside and adjust the brightness, which I don't normally do, so yes, it definitely could have been the cause. So what now? delete the latest kernal or what? And how do I prevent this from happening in the future?

hydrurga · 05-01-2017, 09:06 PM

Quote:

Originally Posted by juntjoo

Thanks, it says 4-26 so it would be right before I noticed which only happened to be because I decided to use my laptop outside and adjust the brightness, which I don't normally do, so yes, it definitely could have been the cause. So what now? delete the latest kernal or what? And how do I prevent this from happening in the future?

If it is the cause of the problem then hopefully it is a temporary regression (a bug in the latest 4.4 kernel) which will hopefully be resolved in a future version.

The first thing to do is to boot into the previous kernel version, 4.4.0-72, to check that the kernel upgrade was indeed the cause.

Do you see the Grub menu when you boot your machine? If so, you can select to use the previous kernel version through that (choose "Advanced Options").

juntjoo · 05-02-2017, 01:22 PM

Quote:

Originally Posted by hydrurga

If it is the cause of the problem then hopefully it is a temporary regression (a bug in the latest 4.4 kernel) which will hopefully be resolved in a future version.

The first thing to do is to boot into the previous kernel version, 4.4.0-72, to check that the kernel upgrade was indeed the cause.

Do you see the Grub menu when you boot your machine? If so, you can select to use the previous kernel version through that (choose "Advanced Options").

thank you. No, I don't have any other options but to just log in.

hydrurga · 05-02-2017, 01:32 PM

Ok. See if this will work for you.

From this page: https://wiki.ubuntu.com/RecoveryMode

Quote:

. Switch on your computer.
. Wait until the BIOS has finished loading, or has almost finished. (During this time you will probably see a logo of your computer manufacturer.)
. Quickly press and hold the Shift key, which will bring up the GNU GRUB menu. (If you see the Ubuntu logo, you've missed the point where you can enter the GRUB menu.)

Some people get better mileage by rapidly tapping the Shift key.

Shadow_7 · 05-02-2017, 03:37 PM

Have you tried using xbacklight?

$ sudo apt-get install xbacklight
$ xbacklight -set 50%

And various other routes.

$ cat /sys/class/backlight/intel_backlight/max_brightness

# echo 2222 > /sys/class/backlight/intel_backlight/brightness

Where 7812 is max_brightness for my hp stream 11. And a value of 0 is pitch black (but the backlight is still probably on).

juntjoo · 05-03-2017, 06:05 PM

Quote:

Originally Posted by Shadow_7

Have you tried using xbacklight?

$ sudo apt-get install xbacklight
$ xbacklight -set 50%

And various other routes.

$ cat /sys/class/backlight/intel_backlight/max_brightness

# echo 2222 > /sys/class/backlight/intel_backlight/brightness

Where 7812 is max_brightness for my hp stream 11. And a value of 0 is pitch black (but the backlight is still probably on).

does xbacklight not have a gui?

how do you uninstall it if you don't like it? I think I'd prefer to find a solution to the standard brightness adjustment method not working.

what is "cat" and "echo 2222"?

Thanks

juntjoo · 05-03-2017, 06:23 PM

Quote:

Originally Posted by hydrurga

Ok. See if this will work for you.

From this page: https://wiki.ubuntu.com/RecoveryMode

Some people get better mileage by rapidly tapping the Shift key.

Thanks. I normally get grub because I have to choose whether to boot into linux or Windows. But that page you linked to, I'm not sure what that is about or how it will help me revert to a previous kernal. Is this just step one then you'll guide me to how I can write to the boot partition to delete the current kernal or something?

hydrurga · 05-03-2017, 11:05 PM

Quote:

Originally Posted by juntjoo

Thanks. I normally get grub because I have to choose whether to boot into linux or Windows. But that page you linked to, I'm not sure what that is about or how it will help me revert to a previous kernal. Is this just step one then you'll guide me to how I can write to the boot partition to delete the current kernal or something?

The grub menu also allows you to temporarily boot up using a previous version of the Linux kernel that you have installed.

What I would like you to do is boot up into the 4.4.0-72 kernel to see if that resolves the problem.

If it does, you can then take action to remedy the problem. That may involve deleting the 4.4.0-75 kernel or installing a kernel from a later line e.g. 4.10 where the problem may have been solved.

The page I linked to was purely to show you how to get the grub screen to show if it wasn't displaying.

Once you get the grub screen, select "Advanced Options" and then 4.4.0-72 (don't choose recovery mode).

juntjoo · 05-04-2017, 03:50 AM

Quote:

Originally Posted by hydrurga

The grub menu also allows you to temporarily boot up using a previous version of the Linux kernel that you have installed.

What I would like you to do is boot up into the 4.4.0-72 kernel to see if that resolves the problem.

If it does, you can then take action to remedy the problem. That may involve deleting the 4.4.0-75 kernel or installing a kernel from a later line e.g. 4.10 where the problem may have been solved.

The page I linked to was purely to show you how to get the grub screen to show if it wasn't displaying.

Once you get the grub screen, select "Advanced Options" and then 4.4.0-72 (don't choose recovery mode).

thanks. I tested all the way down to xxx.63 and got nothing. what other ideas might you have?