Comment 17 for bug 1008867

Although I proposed to quirk these models, upstream developers would like to find out the root cause instead of just disabling rc6. Since https://bugs.freedesktop.org/show_bug.cgi?id=50545 is originally created for #1002170 , I create another entry for this issue, which can be found at https://bugs.freedesktop.org/show_bug.cgi?id=54739