On Sat, Dec 3, 2016 at 1:52 AM, Jani Nikula <jani.nik...@linux.intel.com> wrote: > On Sat, 03 Dec 2016, Matt Turner <matts...@gmail.com> wrote: >> From these instructions, users assume that /sys/class/drm/card0/error >> contains all the information a developer needs to diagnose and fix a GPU >> hang. >> >> In fact it doesn't, and we have no tools for solving them (other than >> stabbing in the dark). Most of the time the error state itself isn't >> even useful because it just shows a hang on a PIPE_CONTROL or similar. >> >> Until a time when the error state contains enough information to >> actually solve a hang, stop telling users to file unsolvable bugs, and >> instead rely on users who know where and how to file a good bug report >> to find their own way there. >> >> Signed-off-by: Matt Turner <matts...@gmail.com> >> --- >> Maybe now's a good time to discuss what *would* be useful to put in the >> error state for debugging hangs. The currently executing shader program >> would be a great place to start. > > I'm wondering why we're getting this patch now, and my guess is that > it's because we have been reassigning the related bugs to Mesa more > actively lately. Is that the case?
No, it's simply because I spent a week going through Bugzilla and realized how incomplete an unactionable the majority of GPU hang reports are. Asking users to report bugs, but not telling them what actually constitutes a bug report, is a recipe for a lot of wasted developer time. I suspect we could improve the usefulness of the reports by directing users to a webpage that gave a few suggestions (tell us what you were doing when the hang occurred would be an obvious one) about filing a bug and then provided a link to Bugzilla. Or even configured Bugzilla to have a default template that requested various bits of information. > IIUC the bug reports are useful for us when it's a kernel bug, but less > useful for you when it's a Mesa bug. And you'd rather have fewer > incoming bugs that you think are unsolvable with the information at > hand. > > Sounds like a bug workflow issue between drm/i915 and Mesa to be ironed > out. Indeed. I'd rather have the information provided in a bug report to actually solve it. I hope having access to the shader program will make many more reports useful. I am also happy to see that there's now a sunset to the GPU hang message.
