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Date:   Tue, 13 Jun 2023 12:27:56 +0200
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Subject: Re: [PATCH v2 0/1] platform/x86: asus-wmi: add support for ASUS
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To:     Luke Jones <luke@ljones.dev>
Cc:     platform-driver-x86@vger.kernel.org,
        =?UTF-8?Q?Barnab=c3=a1s_P=c5=91cze?= <pobrn@protonmail.com>,
        =?UTF-8?Q?Ilpo_J=c3=a4rvinen?= <ilpo.jarvinen@linux.intel.com>,
        linux-kernel@vger.kernel.org, acpi4asus-user@lists.sourceforge.net,
        corentin.chary@gmail.com, markgross@kernel.org, jdelvare@suse.com,
        linux@roeck-us.net
References: <20230505043013.2622603-1-luke@ljones.dev>
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 <ffdd2d13-975e-1c74-0d2b-132ba461a3ee@redhat.com> <5946924.lOV4Wx5bFT@fedora>
From:   Hans de Goede <hdegoede@redhat.com>
In-Reply-To: <5946924.lOV4Wx5bFT@fedora>
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Hi,

On 6/7/23 00:45, Luke Jones wrote:

<snip>

>> I must admit I've lost track a bit of the state of v2 during this
>> discussion.  Can I pick up v2 as is, or were there (other) remarks
>> which need addressing and should I expect a v3 ?
> 
> There will be a V3. I don't anticipate any issues at all with this, and some 
> folks have been using this patch with Gnome and KDE since V2 was submitted.

Ok.


>> ####### Switch to (off-topic) GPU mux discussion ########
> **snip**
>>>> I think the best thing to do here is to just use EFI on machines like
>>>> this. That or put grub in text mode so that it makes BIOS calls to
>>>> display text. Using GRUB_TERMINAL_OUTPUT=gfxterm combined with
>>>> classic BIOS booting will make grub try to directly drive the gfx
>>>> card itself and I'm not surprised that it gets that wrong in this
>>>> case.
>>>> Note I think that just using EFI is prefered over switching grub to
>>>> GRUB_TERMINAL_OUTPUT=console. I would expect
>>>> GRUB_TERMINAL_OUTPUT=console to also work but I'm not sure. I don't
>>>> think that the classic BIOS boot stuff is still tested by laptop
>>>> vendors and esp. not tested with non standard BIOS settings ...
>>>
>>> The grub gfx mode is GRUB_TERMINAL_OUTPUT="console", fedora default in
>>> all cases here. Grub itself shows fine when the MUX mode is in dgpu
>>> mode (aka, internal display connected to dgpu).
>>
>> Ah ok, so I misunderstood and the problem only happens *after* grub?
>>
>> Have I understood that correctly?
>>
>> And this is on Fedora with the nvidia binary driver ?
>>
>> The problem then likely is that the nvidia binary driver is not in
>> the initrd (which is by design since it may need to be rebuild on
>> a driver update while the kernel is kept at the same version,
>> so the initrd won't be rebuild).
> 
> That was indeed the issue. It also creates new problems for when a user wants 
> to use iGPU only via the plain (and frankly not adequate or good) method of 
> simply removing the dGPU from the device tree.
> 
> Currently I maintain the supergfxd tool which is a lot more advanced than the 
> other gpu switchers around, and I expose both the above method, and also PCI 
> hotplug, and the ASUS WMI method (which I now think is used by other vendors 
> also). Hotplug and Asus method can force the device off, and it can't be 
> brought back by a PCI rescan - but to do so safely the Nvidia drivers must be 
> unused and unloaded. I guess I'll need to tweak the boot process of supergfxd 
> and block things until this is done.
> 
> Maybe we can move this to a new topic, because there looks to be a few things 
> to discuss in relation to hybrid laptops, and specifically Nvidia with MUX, 
> and Advanced Optimus.

Yes if you want to discuss this further please start a new mailinglist
thread for this and also please put the dri-devel list on the Cc:

dri-devel@lists.freedesktop.org

Regards,

Hans