On Tue, Nov 17, 2015 at 7:18 PM, Linus Torvalds torvalds@linux-foundation.org wrote:
On Tue, Nov 17, 2015 at 9:53 AM, Olof Johansson olof@lixom.net wrote:
The problem as I see it is that it's unknown how many machines depends on previous behavior. If it's only Pixel 2015 then I think a whitelist would be just fine.
Considering how many problems we historically have had with backlight handling, I would strongly urge people to *not* start going down the whitelist approach.
If the backlight doesn't get set up correctly, the machine might as well be considered dead. Very few people are going to give good reports of it. So the backlight code needs to bend oevr backwards in being robust even more so than most other code, and "whitelist known-working setups" is absolutely the reverse of robust. It's a hack, and it's guaranteed to not be maintainable.
Yes, yes, we have whitelists for other things. I hate them in other places too. But things like "this device has very odd audio configuration" is very different from "this machine appears dead on boot", for example.
So reverting quickly is definitely the right thing to do. Or applying the patch that apparently fixes it for Olof, and hopefully fixes it in general - without any kind of random "on _this_ machine we do _that_" crap.
If drm people don't want the revert, send me a pull request with the fix.
Imo revert. With all the QA awol fail we've suffered the past few months we've become a bit too lax imo with reverting fast, and the point of the split-out commit was to allow exactly that.
On top I don't really like the casting Maarten's current hack does, we probably need a per-encoder ->sanitize hook for this stuff. Better to retry for 4.5. Can you pls push the revert?
Thanks, Daniel