Continuing the posts’ streak, today we are going to see how to eliminate the PWM flickering problem that arises on some of the ThinkPad laptops of early 2010-th. The proposed solution is specific for the laptops equipped with Intel GPU’s (Intel i915 only) running Linux.

This summer I’ve acquired a second laptop, an old ThinkPad X220, to have something more portable at hand in complement to my main ThinkPad T430. Today I’ve decided to finally patch my X220, because with time the eye strain has become more and more noticeable. Both of the machines encounter the same screen flickering issue even after the upgrade of their screens to the IPS versions. And even though I already corrected the problem on my T430 about 2 years ago, I’ve completely forgot how to do it by now. After some search on the Internet, I’ve found the solution and this post serves mostly to keep it by hand, just in case.