Created attachment 115778 [details] [review] debuging patch Your dpcd is indeed getting corrupted somehow. I can't see how though. The attached patch (please drop your hardcode to 2 patch when you apply this one) should workaround the issue by re-fetching the dpcd when required, but doesn't fix the root cause. Please attach the dmesg output with this patch applied as well. I'd like to see how often it's getting corrupted.