On Tue, Jun 25, 2013 at 11:30:37PM +0200, Yves-Alexis Perez wrote: > On mar., 2013-06-25 at 22:14 +0100, Matthew Garrett wrote: > > Which, as we've already established, you don't - Lenovo broke it. Your > > Thinkpad claims to have 100 available levels, and most of them don't > > work. The kernel has no way of knowing which levels work and which > > don't, so leaving this up to the kernel won't actually fix your system > > either. > > I was referring to ?standardize the behaviour by leaving up to > userspace?. A lot of thinkpads (for example) (all the pre-windows 8 > ones) have a perfectly working ACPI backlight interface. And this patchset won't alter their behaviour. > Also, if the kernel has no way of knowing which levels work, I fail to > see how userspace can do better. It can't. That's why this patchset disables the ACPI interface on Windows 8 systems. > I understand that switching to intel_backlight instead of acpi_video0 > follows what Windows 8 recommends but for me it looks orthogonal to the > fact ACPI methods now have some awkward (Lenovo) or broken (Dell). I > mean, it's not the first time firmware people break some kernel > behavior. I know it's usually not easy to contact them, but shouldn't > those methods be fixed, instead of somehow blindly switching to graphic > drivers? No. The correct answer to all firmware issues is "Are we making the same firmware calls as the version of Windows that this hardware thinks it's running". If Windows 8 doesn't make these calls, we shouldn't make these calls. -- Matthew Garrett | mjg59 at srcf.ucam.org
