Message-ID: <172e8971-f160-b04e-3250-b8743f31c820@infradead.org>
Date:   Tue, 11 Jan 2022 12:54:09 -0800
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Subject: Re: Unable to unselect VGA_ARB (VGA Arbitration)
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To:     Paul Menzel <pmenzel@molgen.mpg.de>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>
Cc:     David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
References: <b72ad376-7a42-1ff2-701d-7fb2f3333c64@molgen.mpg.de>
From:   Randy Dunlap <rdunlap@infradead.org>
In-Reply-To: <b72ad376-7a42-1ff2-701d-7fb2f3333c64@molgen.mpg.de>
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Hi Paul,

On 1/11/22 12:28, Paul Menzel wrote:
> Dear Linux folks,
> 
> 
> I am using Linux 5.16, and I am unable to unset `VGA_ARB` in Kconfig (`make menuconfig`). I have an Asus F2A85-M PRO with an AMD A6-6400K APU (integrated Radeon graphics device), so no legacy stuff.
> 
> From `drivers/gpu/vga/Kconfig`:
> 
> ```
> config VGA_ARB
>         bool "VGA Arbitration" if EXPERT

You can modify VGA_ARB if you set ^^^^^^ "EXPERT".

>         default y
>         depends on (PCI && !S390)
>         help
>           […]
> 
> config VGA_ARB_MAX_GPUS
>         int "Maximum number of GPUs"
>         default 16
>         depends on VGA_ARB
>         help
>           […]
> 
> config VGA_SWITCHEROO
>         bool "Laptop Hybrid Graphics - GPU switching support"
>         depends on X86
>         depends on ACPI
>         depends on PCI
>         depends on (FRAMEBUFFER_CONSOLE=n || FB=y)
>         select VGA_ARB
>         help
>           […]
> ```
> 
> But in `make menuconfig` I am unable to unselect it.
> 
>     -*- VGA Arbitration
> 
> and the help says:
> 
>     Symbol: VGA_ARB [=y]
>     Type  : bool
>       Depends on: HAS_IOMEM [=y] && PCI [=y] && !S390
>       Visible if: HAS_IOMEM [=y] && PCI [=y] && !S390 && EXPERT [=n]
>       Location:
>         Main menu
>          -> Device Drivers
>            -> Graphics support
>     Selected by [n]:
>       - VGA_SWITCHEROO [=n] && HAS_IOMEM [=y] && X86 [=y] && ACPI [=y] && PCI [=y] && (!FRAMEBUFFER_CONSOLE [=y] || FB [=y]=y)
> 
> So, VGA_SWITCHEROO is not set, and, therefore, as `Selected by [n]:` suggests, I thought I’d be able to deselect it.
> 
> It’d be great if you could help me out.
> 
> 
> Kind regards,
> 
> Paul

-- 
~Randy