Hi, On 2022-08-12 09:59+0200, Hans de Goede wrote: > Date: Fri, 12 Aug 2022 09:59:29 +0200 > From: Hans de Goede <hdegoede@xxxxxxxxxx> > To: Luke Jones <luke@xxxxxxxxxx> > Cc: andy.shevchenko@xxxxxxxxx, pobrn@xxxxxxxxxxxxxx, pavel@xxxxxx, > platform-driver-x86@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v3 6/6] asus-wmi: Support the hardware GPU MUX on some > laptops > User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 > Thunderbird/91.12.0 > > Hi, > > On 8/12/22 00:01, Luke Jones wrote: > > Hi Hans, > > > > On Thu, 2022-08-11 at 15:53 +0200, Hans de Goede wrote: > >> Hi, > >> > >> On 8/9/22 04:50, Luke D. Jones wrote: > >>> Support the hardware GPU MUX switch available on some models. This > >>> switch can toggle the MUX between: > >>> > >>> - 0, Dedicated mode > >>> - 1, Optimus mode > >>> > >>> Optimus mode is the regular iGPU + dGPU available, while dedicated > >>> mode switches the system to have only the dGPU available. > >>> > >>> Signed-off-by: Luke D. Jones <luke@xxxxxxxxxx> > >> > >> I see that you have replied to this that it needs more work. > >> > >> Besides it needing more work, ideally this should hook into > >> the existing vga-switcheroo mechanism for this. Can you take > >> a look at that please? > >> > >> I think this might be the first non GPU driver doing vga- > >> switcheroo stuff. So this may be something to discuss > >> on the dri-devel list. > > > > I'm not sure how this would work. In typical ASUS fashion they do non- > > standard stuff. This switch is a basic toggle that requires a reboot to > > enable after writing to the ACPI method, after reboot the dGPU becomes > > the only visible GPU on the system and (this GPU) can not be suspended. > > > > In short: it toggles the laptop from discrete-only mode, and optimus > > mode, requiring a reboot to switch. > > > > From what I understand of switcheroo it is more to manage having dual > > (or more) GPU available during runtime, and manage the power states, > > offload etc. > > Right, I did not realize this requires a reboot, that would be > something to mention in the Documentation bits accompanying the patch. > > This is also a reason why it is good to have the docs update in > the same patch as adding the functionality, because the docs may > help with reviewing. > > Anyways I agree that if this requires a reboot then using > the vga switcheroo stuff is not applicable. So we can just go with > a simple(ish) asus-wmi sysfs attribute. Would this not fit the existing "firmware-attributes" class? It even has a flag to signal that a reboot is required after an attribute has been changed. Maybe it is overkill to use it only for this, though. > > I have a vastly improved patch for this prepared now. Because of how > > the actual feature works (and the above explanation) it must be under > > the asus-nb-wmi sysfs (next to the dgpu_disable and egpu_enable toggles > > which are also unusual and non-standard work-arounds of Windows > > issues). > > Ack, sounds good. Thomas
