On Thursday, November 26, 2015 07:53:20 AM Andy Lutomirski wrote: > On Thu, Nov 26, 2015 at 6:09 AM, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote: > > On Wednesday, November 25, 2015 05:28:54 PM Andy Lutomirski wrote: > >> On Mon, Nov 23, 2015 at 11:37 AM, Darren Hart <dvhart@xxxxxxxxxxxxx> wrote: > >> > On Mon, Nov 23, 2015 at 11:25:30AM -0800, Andy Lutomirski wrote: > >> >> Without this patch, wmi devices are in /sys/virtual/wmi. They're > >> >> logically children of the ACPI WMI device, so slot them into the > >> >> device hierarchy. With this change, on my laptop, they end up in > >> >> /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C14:00/wmi and > >> >> /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C14:01/wmi. > >> >> > >> >> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx> > >> > > >> > I'd like to hear from some of the main contributors to this driver: > >> > > >> > Matthew? > >> > Carlos? > >> > Len? > >> > > >> > Any cocnerns on this change? > >> > > >> > My initial concern is about changign how we expose this to userspace, but I > >> > believe where it appears in the /sys/devices FS is NOT part of the > >> > kernel-userspace interface commitment (per sysfs-rules.txt). > >> > >> > >> Let's drop this, actually. I have mostly-working patches to make wmi > >> into an actual bus driver, and this intermediate step seems like it'll > >> just confuse people. > >> > >> Question, though: where do the WMI devices belong? Multiple choice: > >> > >> /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C14:01/[GUID] > >> > >> /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C14:01/wmi/[GUID] > >> > >> /sys/devices/platform/PNP0C14:01/[GUID] > >> > >> /sys/devices/platform/PNP0C14:01/wmi/[GUID] > >> > >> Currently I've implemented the first one because it's the smallest diff. > > > > That probably is not the right choice, though. > > > > ACPI "devices" are counterparts of DT device nodes and having other things > > exported under them would be quite confusing. In fact, you can argue that > > the whole /sys/devices/LNXSYSTM:00/ directory should be located under > > /sys/firmware/acpi, but it turns out to be difficult to move it there > > for various reasons. > > > > Personally, I'd go for the last one. > > Mechanically, how do I do that? Should I register as just a platform > driver and use acpi_device_install_notify_handler to get the ACPI > notifications, or should I register as *both* a platform driver and > ACPI driver? If you have a platform device for this thing, registering an ACPI driver for it is pretty much as valid as registering a driver for a DT device node. So yes, a platform driver is a way to go here IMO. Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
