On Jun 01 2017 or thereabouts, Bastien Nocera wrote: > On Thu, 2017-06-01 at 20:46 +0200, Benjamin Tissoires wrote: > > Hi, > > > > Sending this as a WIP as it still need a few changes, but it mostly > > works as > > expected (still not fully compliant yet). > > > > So this is based on Lennart's comment in [1]: if the LID state is not > > reliable, > > the kernel should not export the LID switch device as long as we are > > not sure > > about its state. > > > > That is the basic idea, and here are some more general comments: > > Lv described the 5 cases in "RFC PATCH v3" regarding the LID switch. > > Let me rewrite them here (they are in patch 2): > > > > 1. Some platforms send "open" ACPI notification to the OS and the > > event > > arrive before the button driver is resumed; > > 2. Some platforms send "open" ACPI notification to the OS, but the > > event > > arrives after the button driver is resumed, ex., Samsung N210+; > > 3. Some platforms never send an "open" ACPI notification to the OS, > > but > > update the cached _LID return value to "open", and this update > > arrives > > before the button driver is resumed; > > 4. Some platforms never send an "open" ACPI notification to the OS, > > but > > update the cached _LID return value to "open", but this update > > arrives > > after the button driver is resumed, ex., Surface Pro 3; > > 5. Some platforms never send an "open" ACPI notification to the OS, > > and > > _LID ACPI method returns a value which stays to "close", ex., > > Surface Pro 1. > > In which case does the Surface 3 lie? I believe we still needed your > "gpiolib-acpi: make sure we trigger the events at least once" patch to > make that one work.
Well, the surface 3 is using a different driver for the LID switch (surface3-wmi). From what I can remember, we don't need this patch when using this driver (which is why I did not submitted it further). But I might be wrong... Cheers, Benjamin
