Comment 68 for bug 1009312

So after another couple of months, I've managed to do more testing, and I may have found something useful. First off, two fresh, stable versions of the Ubuntu kernel have shown the bug: v3.2.0-56 (64-bit) and v3.5.0-44 (32-bit). Also, the most recent package from the Ubuntu mainline kernel PPA, v3.13.0-rc3 (built Dec. 6), showed the bug and failed to boot. I confirmed the bug by looking at the old dmesg log after rebooting into a working kernel.

On the positive side, after a little more free-time and thinking about the problem, I can give you a commit that may be canceling out the effect from Xiao Guangrong's earlier patch. Instead of using git-bisect, I narrowed down the problem to a small range from previous tests, then manually checked the merges in the mainline kernel's history. After tracing the regression to a simple merge, I rebased the short side branch leading to it onto the preceding, bug-free commit. I don't know if this method would give false results, but I figured since the merge itself involved no extra changes and the rebase didn't cause any conflicts, it should be useful.

The patch where the bug reappeared for me was:
ee8209fd026b074bb8eb75bece516a338a281b1b by Andy Shevchenko

Hope this helps some, and let me know if there's anything else I could try.