Sending this message again because it previously got sent only to Lukas by mistake. Hi, Not sure whether it's relevant, but this user here also claims that without setting the os to macOS, the external GPUs had issues. https://www.phoronix.com/forums/forum/software/general-linux-open-source/1479158-linux-6-11-efi-will-fake-that-it-s-booting-apple-macos-to-fix-some-dual-gpu-macs?p=1479205#post1479205 ________________________________________ From: Aditya Garg <gargaditya08@xxxxxxxx> Sent: 23 July 2024 21:55 To: Lukas Wunner Cc: Ard Biesheuvel; linux-efi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Hans de Goede; Kerem Karabay; Orlando Chamberlain; sharpenedblade@xxxxxxxxx Subject: Re: [PATCH v3 0/2] efi/x86: Call set_os() protocol on dual GPU Macs Sending this message again as for some reason it got sent only to Lukas: Full model name: Mac mini (2018) (Macmini8,1) The drive link below has the logs: https://drive.google.com/file/d/1P3-GlksU6WppvzvWC0A-nAoTZh7oPPxk/view?usp=drive_link ________________________________________ From: Lukas Wunner <lukas@xxxxxxxxx> Sent: 18 July 2024 00:28 To: Aditya Garg Cc: Ard Biesheuvel; linux-efi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Ard Biesheuvel; Hans de Goede; Kerem Karabay; Orlando Chamberlain; sharpenedblade@xxxxxxxxx Subject: Re: [PATCH v3 0/2] efi/x86: Call set_os() protocol on dual GPU Macs On Wed, Jul 17, 2024 at 04:35:15PM +0000, Aditya Garg wrote: > For the Macs having a single GPU, in case a person uses an eGPU, > they still need this apple-set-os quirk for hybrid graphics. I don't quite follow. You mean the integrated graphics are disabled by EFI firmware if an eGPU is attached? This sounds like a bug on Apple's part: The panel can be switched between integrated graphics and discrete graphics, but an external display can't be switched between eGPU and iGPU. Is the person affected using the latest EFI firmware update from Apple? We need more information before we can devise a way to solve the issue: - Exact model name (I'd be surprised if this affected pre-Haswell models) - Full dmesg output with command line option "dump_apple_properties" (EFI drivers provide various properties for Thunderbolt-attached devices and graphics cards, those could be queried to recognize the situation causing the issue) - Full lspci output with and without eGPU attached Perhaps you can open a bug at bugzilla.kernel.org and attach the files there. Thanks, Lukas