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Brightness function keys fail to change brightness levels in Fedora 20

asked 2014-08-26 07:30:41 -0500

jflory7 gravatar image

updated 2014-08-26 07:32:16 -0500

To introduce this question, I would like to cite a few places that I have pulled information from prior to asking this question. I referred to this AskFedora question from Fedora 16 as well as this forum post about the same issue I'm about to describe.

I have a Toshiba Satellite C55-A laptop running Fedora 20 with the latest Linux kernel available. One thing I have always noticed that has bothered me on my laptop is that the Fn+F2 and Fn+F3 key combination is unable to actually change the brightness. Like in the AskFedora question linked above, my brightness levels will also go down or up one "notch", but there is no actual change in screen brightness and the levels can only go down one or up one.

I have tried reinstalling bash (sudo yum reinstall bash), but this did not have the same effect as it did for others on the Fedora Forums and AskFedora.

So, it would appear that I'm stuck! I'd really like to get these working, so any thoughts are welcome. Also, for additional reference, I only recently enabled the proper graphics drivers (see here), so I'm not sure if it would be an issue with that kind of thing.

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I have the exact same problem. I have a Toshiba Satellite C50-A with Fedora 20 (64-bit) and latest kernel. This remains my only outstanding bug after switching my laptop from Windows 7. All the answers I have found online have not worked.

cgonz31 gravatar imagecgonz31 ( 2014-08-26 08:14:15 -0500 )edit

@cgonz31: Does your laptop automatically load the proper drivers at startup, or did you have the edit the kernel bootup command? I know this was an issue with mine a while back, and I'm just wondering if it's related.

jflory7 gravatar imagejflory7 ( 2014-08-27 13:10:33 -0500 )edit

I did not edit the kernel bootup command. I can list the loaded kernel modules with lsmod but I do not know which are the proper drivers or whether they are being loaded. I did a clean install of Fedora on my laptop and everything worked just fine (except for the brightness issue). Thus, I did not knowingly install other drivers. Some might have been installed through yum post OS installation but I do not remember.

cgonz31 gravatar imagecgonz31 ( 2014-08-27 23:29:36 -0500 )edit

@cgonz31 Hmmm. I know I had to add the i915 driver for my Intel i3 with its integrated graphics. I made a bug report on the Red Hat bug tracker here. However, it seems that this is likely unrelated.

jflory7 gravatar imagejflory7 ( 2014-08-29 21:21:41 -0500 )edit

I have the same model as @cgnoz31 but the update to the newest kernel didn't work for me. F3 displays a battery indicator and F4 suspends the laptop. (live cd wouldn't display anything without nomodeset but then removing this param after install meant the correct graphics driver was used)

hypnos360 gravatar imagehypnos360 ( 2014-10-05 12:06:00 -0500 )edit

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answered 2014-09-14 19:31:28 -0500

cgonz31 gravatar image

You can try the newest kernel, 3.16.2-200.fc20.x86_64. That solved the problem for me. Don't know why as I am a newbie Linux user. I hope it works for you.

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Yeah, sure enough, this fixed it for me as well. Go figure. Thanks for the tip!

jflory7 gravatar imagejflory7 ( 2014-09-14 23:37:14 -0500 )edit

Ironicaly kernel 3.15 works for me, and the update to 3.16 broken it (o-o)

Ivan Augusto gravatar imageIvan Augusto ( 2014-09-16 15:49:41 -0500 )edit

@Ivan Augusto: Strange… what type of laptop do you have, Toshiba?

jflory7 gravatar imagejflory7 ( 2014-09-19 23:29:46 -0500 )edit

@jflory7: no, is a Brazilian vendor, SIM+, why? Any solutions?

Ivan Augusto gravatar imageIvan Augusto ( 2014-09-21 08:42:27 -0500 )edit

@Ivan Augusto: Your issue may be different from this one. My laptop is a Toshiba C55-A, and this resolved the issue for me. Perhaps try asking a new question!

jflory7 gravatar imagejflory7 ( 2014-09-21 21:14:11 -0500 )edit

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Asked: 2014-08-26 07:30:41 -0500

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Last updated: Sep 14 '14