On 23 August 2021 22:13:45 BST, Alyssa Rosenzweig alyssa@collabora.com wrote:
When locking a region, we currently clamp to a PAGE_SIZE as the minimum lock region. While this is valid for Midgard, it is invalid for Bifrost,
While the spec does seem to state it's invalid for Bifrost - kbase didn't bother with a lower clamp for a long time. I actually think this is in many ways more of a spec bug: i.e. implementation details of the round-up that the hardware does. But it's much safer following the spec ;) And it seems like kbase eventually caught up too.
Yeah, makes sense. Should I drop the Cc: stable in that case? If the issue is purely theoretical.
I think it might still be worth fixing. Early Bifrost should be fine, but something triggered a bug report that caused kbase to be fixed, so I'm less confident that there's nothing out there that cares. Following both kbase and the spec seems the safest approach.
Thanks, Steve