Messages in this thread | | | From | <> | Subject | RE: [PATCH v3 0/4] dell-wmi: Changes in WMI event code handling | Date | Wed, 22 Jun 2016 13:20:12 +0000 |
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> > I talked to the EC team about this a while back when it was first implemented. > > That's not possible without _OSI detection of Linux. _OSI detection > > could be used to relay to the EC to behave differently, but otherwise > > the EC will have no idea what OS it's on for which way to behave. > > ACPI code should not behave differently for different operating systems. > If there is bug in kernel, report bug to kernel, subtree maintainer for fixing it. > And not doing workaround and hacks in ACPI.
This isn't ACPI code, this is EC code.
> > In this case there could be (standardized) ACPI function for turning off this > nonsense functionality and supported kernel could call it. >
I think you might have interpreted my response differently than I intended. I know that the Linux kernel has chosen to respond as the latest Windows version for _OSI, and that's why it's not possible to do a different behavior for Linux and Windows.
If there is a desire to go down the route of having different behavior for what the EC does in different OS'es, _OSI is only way to accomplish this.
> Is not there such ACPI function? Or Dell specific SMBIOS call? >
I'm not aware of any standard ACPI function or Dell function for this type of request. Last time this was discussed I was told the EC would emit single display scan code for Windows < 7 (as Windows Vista and earlier doesn't support super + p). Windows > 7 (as detected by _OSI and passed to EC) will emit super + p.
> > I don't remember all the history behind the switch over from a single > > scan code To <super> + P, but I think it's along the lines of Windows > > 8/Windows 10 allow you to iterate the display selection menu based > > upon holding super and pressing P multiple times and waiting for you to stop. > > Windows systems doing stupid things and fixing their bugs in ACPI is wrong. It > broke for example this key on all other systems (Linux too). >
There's no bug in this behavior, it's intended behavior.
Like I said, previously display switch hotkey would immediately cycle outputs. The behavior followed with super + p allows for OS to toggle through a menu of outputs in this OS.
" Toggle through the projection mode (new with Windows 7)." https://msdn.microsoft.com/en-us/library/ms971323.aspx
> > Sending a single scan code will change displays immediately, so having > > the EC send super+p unifies the behavior of fn-f8 and super+p. > > And due to this OS/kernel cannot distinguish between Fn-F8 and Super+p keys...
Which is intended behavior from system designer's perspective.
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