Hi, On 1/23/23 14:58, Lukas Wunner wrote: > On Mon, Jan 23, 2023 at 01:38:37PM +0100, Hans de Goede wrote: >> On 1/23/23 13:09, Lukas Wunner wrote: >>> On Mon, Jan 23, 2023 at 12:37:47PM +0100, Hans de Goede wrote: >>>> Some apple laptop models have an ACPI device with a HID of APP000B >>>> and that device has an IO resource (so it does not describe the new >>>> unsupported MMIO based gmux type), but there actually is no gmux >>>> in the laptop at all. >>>> >>>> This patch-series improves the drivers/acpi/video_detect.c so that >>>> it no longer tries to use the non present gmux in this case. >>>> >>>> Note I'm still waiting for testing feedback from the reporter of >>>> this problem. But from the logs the problem is clear >>>> (the logs show: "apple_gmux: gmux device not present") >>> >>> Please provide a link to the original report. I would also like to >>> know the exact MacBook model used and I would like to see full dmesg >>> output as well as an acpidump. >> >> I only have a report by private email. This does include full dmesg >> output and an acpidump. I will forward this to you in a private >> email. >> >> The reporter describes their model as a macbookpro8,1. >> >>> What you're saying here is that there's a fake APP000B device present >>> in DSDT >> >> Yes that is exactly what I'm saying. > > That's a 2011 13" MacBook Pro which indeed does not have dual GPUs. > > I searched for other affected models and this seems to be more common > than I thought: > > MacBookPro5,4 > https://pastebin.com/8Xjq7RhS > > MacBookPro8,1 > https://linux-hardware.org/?probe=e513cfbadb&log=dmesg > > MacBookPro9,2 > https://bugzilla.kernel.org/attachment.cgi?id=278961 > > MacBookPro10,2 > https://lkml.org/lkml/2014/9/22/657 > > MacBookPro11,2 > https://forums.fedora-fr.org/viewtopic.php?id=70142 > > MacBookPro11,4 > https://raw.githubusercontent.com/im-0/investigate-card-reader-suspend-problem-on-mbp11.4/master/test-16/dmesg > > These are 13" and 15" models from the pre-retina and retina era > (2009 - 2015). None of them have dual GPUs. (Only a subset of > the 15" and 17" models had dual GPUs.) Apple sloppily included > a GMUX device on all of them and it wasn't a problem so far > because the gmux driver detects non-presence and bails out, > but it throws off the new backlight algorithm. > > This is really sad. :( > > Please add a Reported-by to your commits I was about to say that Emmanouil may want to keep their email private. But I see you've already added them to the Cc, so now the email is part of the platform-driver-x86 archives. Emmanouil, is it ok if I add a line like this: Reported-by: Emmanouil Kouroupakis <kartxxx@xxxxxxxxx> to the commit message of v2 of the patches ? This gives you credit for reporting the bug, but it also exposes your email address in public places. > as well as the list I've > provided above so that we've got a complete record in the git history. Ack, I'll add the list of devices to v2 of the patches. Regards, Hans
