From: Jason Ekstrand <ja...@jlekstrand.net> On Wed, 11 Mar 2015 22:50:47, Matthew Garrett <mj...@srcf.ucam.org> wrote: > The ACPI spec describes _REV as: > > "This predefined object evaluates to the revision of the ACPI Specification > that the specified \_OS implements" > > We've been assuming that this should increment as ACPICA gains support for > new versions of the spec. Unfortunately, Windows always reports "2" for this > value and vendors are now using this as a means to tell whether a system is > running Windows or Linux. From an HP Envy 15: > > If (LOr (LEqual (_REV, 0x03), LEqual (_REV, 0x05))) > > From a Dell XPS 13: > > If ((_REV == 0x05))
I can confirm that on my 2015 Dell XPS 13, this patch fixes both the audio and suspend/resume. I'm running a build of Linus' master branch as of some time this morning. Without this patch applied I have no audio and suspend fails leaving the system unresponsive but the keyboard light still on and the fan running indefinitely. With this patch, I get audio and suspend/resume works normally. --Jason Ekstrand -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
