Hi, > From: Bastien Nocera [mailto:hadess@xxxxxxxxxx] > Subject: Re: [PATCH] ACPI / button: Avoid using broken _LID on Surface tablet > > On Fri, 2016-03-04 at 03:37 +0000, Zheng, Lv wrote: > <snip> > > > > > I'm not happy about the "fix" for this problem either, but blaming > > > user-space for this is harsh, given the API exported by the kernel > > > and > > > how pretty much every laptop worked. > > > > > [Lv Zheng] > > It worked for so many years on top of traditional x86 laptops where > > the LID open event is handled by the BIOS to trigger a wake GPE. > > Now we are talking about runtime idle systems where resuming from the > > s2idle invokes no BIOS code. > > The new case is still working on Windows. > > Which forces us to re-consider the kernel API of the ACPI LID. > > The current kernel API works on 99% of machines up until now, user- > space could not have been expected to know that the Lid status might be > incorrect on some machines, it had no way to know that, there was no > documentation saying "don't use the Lid status outside of Lid status > change events". > > We either need to extend the current API to export the fact that we > should ignore the LID status outside of events, or we need a new API. > > (We could fix this without any kernel changes, but we really need the > kernel to document that fact, and export it to user-space) > > This is something you should have said at the start of the mail, > instead of repeatedly saying that user-space was broken. User-space > behaviour hasn't changed there for more than 10 years, and I'm fairly > certain it's worked the same way as APM (on x86) and PMU (on Mac PPC > machines) did. [Lv Zheng] If you want a documentation fix. It seems we need to fix ACPI spec first by clarifying this behavior. By submitting ACPI spec change, we can also gain MS confirmation. So please wait a bit longer to have this clarified. Thanks -Lv > > Cheers ��.n��������+%������w��{.n�����{�����ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
