I love discovering new tools.
Lately my work on Ubuntu Linux kernels has had me paying closer attention to the Intel open source graphics drivers.
I’ve come across a few tools that are handy to developers and people with more advanced troubleshooting skills. One of those is intel_reg_dumper, which (not surprisingly) dumps the values of a whole bunch of internal registers from the graphics card. This comes as part of the xserver-xorg-video-intel-dbg package.
On Ubuntu you can install that with this rune:
sudo apt-get install xserver-xorg-video-intel-dbg
[UPDATE] this tool will be moving to the intel-gpu-tools package. Thanks to tormod on IRC for that info!
Note to self: See what other goodies are in that package
Why is this tool useful? I discovered the tool because I was following an email thread on a development list about high power consumption during suspend. By comparing register contents before and after the problem appeared, the troubleshooter was attempting to see whether there were associated register changes.
I can also see this being useful if you’re trying to debug problems with monitor capabilities – by examining the output you can tell a lot about the video timing that’s been selected – here’s an excerpt:
(II): HTOTAL_B: 0x05a704ff (1280 active, 1448 total)
(II): HBLANK_B: 0x05a704ff (1280 start, 1448 end)
(II): HSYNC_B: 0x054f052f (1328 start, 1360 end)
(II): VTOTAL_B: 0x0336031f (800 active, 823 total)
(II): VBLANK_B: 0x0336031f (800 start, 823 end)
(II): VSYNC_B: 0x03280322 (803 start, 809 end)
(there are over 200 registers dumped for my graphics card)