Feedback on the Lenovo Thinkpad T510

Asked by Tom Gelinas on 2011-07-03

The brightness controls of Lenovo laptops with NVIDIA NVS 3100M or Quadro FX 880M GPUs work while running Nouveau or when using a text mode VT, but not while running X and using proprietary NVIDIA drivers. It is possible to force the NVIDIA driver to control the backlight under X, but causes a buzzing sound that is not audible when using Nouveau. This issue has been reported numerous times over the past 18 months, including a bug filed with NVIDIA's bug reporting system that has received no official response.

More detailed reports and supporting information can be found in Launchpad bug 562005.
https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers/+bug/562005

Is a functional backlight necessary for a laptop to attain Ubuntu hardware certification?
Thank you.

Question information

Tom Gelinas (tomgelinas) said : #1

To underscore the problem: the proprietary NVIDIA driver does not properly control the backlight of the following Lenovo ThinkPad models: T410, T510, W510, T420, T520 and W520. The buzzing issue has been confirmed on models T410 and T510.

Hi,

To answer your question directly, it is not *required* for brightness keys to function on a system in order for it to be certified - a note is added on the systems certification page saying 'Brightness keys not supported'. The backlight would have to be at an acceptable level to begin with though.

Note that the T510 you asked the question about is not certified for the configuration with NVidia graphics (the certified configuration has Intel graphics) but some of the other models you mention have been and have the note about brightness keys not working.

During certification we don't tend to apply hacks so would probably have not encountered the buzzing problem.

Thanks,

Tom Gelinas (tomgelinas) said : #3

My apologies, I selected the wrong T510 when creating this report. I meant to point to http://www.ubuntu.com/certification/hardware/201101-7181:201103-7375 , which has NVIDIA graphics and is Certified for use under 11.04. It may be worthwhile to add a note for this model. Is there an OEM liason team for example that could more appropriately report this issue to Lenovo? This is a very popular series of hardware. Thanks again!

Tom Gelinas (tomgelinas) said : #4

If the backlight is turned down on the BIOS screen, in MS Windows or in a VT under linux, the dim level will be retained in Ubuntu. The backlight level is persistent between reboots, too. This could potentially be unusably dim, but it may be common sense for a person to restart their computer and modify the levels before Ubuntu boort or even boot into Windows to change it.

Hi Tom,

We will check if the problem with the backlight is present on the T510 we have, since there is no note suggesting any problem on the certification entry, but obviously you and others report that the backlight is broken when using the proprietary NVidia drivers (which are required for making Unity work)

Thanks,

Tom Gelinas (tomgelinas) said : #6

This issue has not yet been resolved.

Tom Gelinas (tomgelinas) said : #7

In the most polite manner possible, I want to bump this bug. This issue persists.

Jeff Lane (bladernr) said : #8

I'm going to call this Answered... I realize it's not resolved, but this isn't a bug resolution or technical support venue. The bug you have linked to is still open and being tested, however it's difficult to get any sort of fix in the proprietary nVidia drivers. From a certification point of view, Brendan said, and you agreed, that the certification is based on the nouveau driver working properly, even if it doesn't have the full feature set and battery-life fixes that the nVidia proprietary driver has.

Unfortunately, we can't actually fix nVidia's drivers for them. So I'm going to mark this as Answered and close it out, BUT please understand that this will NOT close the actual bug down, only this Question.

FWIW, I have an nVidia card myself (thankfully not one that's overly problematic) and have felt the pain of nVidia driver problems myself. IN my case, I can't use nouveau because it doesn't support anywhere near the resolution I want to run, which is a minor quibble to many people anyway.

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