Hi,
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.
> and I have a hard time believng that.
Yes that seems to be exactly what is happening. If you look at
the drivers/platform/x86/apple-gmux.c code that is pretty much
the only scenario which leads to the:
apple_gmux: gmux device not present
message getting logged; and it seems to me that the reason that
check is there likely is exactly because of such machines
actually existing.
And /sys/class/backlight contains only intel_backlight
suggesting that this is not a hybrid gfx machine. Which also
matches with the specs which I can find for the macbookpro8,1.
Yet there is an APP000B device present in the DSDT, here is
the relevant bit of the DSDT:
Device (GMUX)
{
Name (_HID, EisaId ("APP000B")) // _HID: Hardware ID
Name (_CID, "gmux") // _CID: Compatible ID
Name (_STA, 0x0B) // _STA: Status
Name (_CRS, ResourceTemplate () // _CRS: Current Resource Settings
{
IO (Decode16,
0x0700, // Range Minimum
0x07FF, // Range Maximum
0x01, // Alignment
0xFF, // Length
)
})
Name (_PRW, Package (0x02) // _PRW: Power Resources for Wake
{
0x16,
0x03
})
Scope (\_GPE)
{
Method (_L16, 0, NotSerialized) // _Lxx: Level-Triggered GPE, xx=0x00-0xFF
{
Notify (\_SB.PCI0.LPCB.GMUX, 0x80) // Status Change
}
}
Name (GMGP, 0x16)
Method (GMSP, 1, NotSerialized)
{
If ((Arg0 <= 0x01))
{
GP06 |= Arg0
}
}
Method (GMLV, 0, NotSerialized)
{
Return (GP06) /* \GP06 */
}
}
}
Regards,
Hans
