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From: Jan Engelhardt <>
Subject: Linux hangs at ACPI init on Medion P15648 MD63490
Date: Fri, 14 Feb 2020 20:28:52 +0100 (CET)
Message-ID: <nycvar.YFH.7.76.2002141734590.24119@n3.vanv.qr> (raw)


I have a problem with a certain x86 laptop, and judging from the
kernel's output, this looks very much like a broken ACPI table.
Versions tried are 5.3.8 (Fedora31 liveimage), 5.5.2 (openSUSE
Tumbleweed installer) and 5.6.0-rc1+
(b19e8c68470385dd2c5440876591fddb02c8c402; self compile), all
exhibiting the same hang.

The last messages emitted by 5.6.0-rc1+ are:

	ACPI: 11 ACPI AML tables successfully acquired and loaded
	ACPI: EC: EC started
	ACPI: EC: interrupt blocked
	ACPI: \: Used as first EC
	ACPI: \: GPE=0x10, IRQ=-1, EC_CMD/EC_SC=0x66, EC_DATA=0x62
	ACPI: EC: Boot ECDT EC used to handle transactions

The full boot procedure is made available at [79MB].
Curiously, FreeBSD 12.1 can be booted without issues, so either they
already workaround the issue, or don't trigger it in the first place.

After about 20 minutes, the kernel issues a stack trace. [4.2M]; this seems to repeat every 
20 minutes:

	Task swapper blocked for more than 491 seconds.
	[a few frames more]

For comparison, a (vastly) different laptop with a proper firmware,
the EC messages go like this:

	<Fujitsu U728 for comparison>
	ACPI: EC: EC started
	ACPI: EC: interrupt blocked
	ACPI: \_SB_.PCI0.LPCB.EC__: Used as first EC
	ACPI: \_SB_.PCI0.LPCB.EC__: GPE=0x22, EC_CMD/EC_SC=0x66, EC_DATA=0x62
	ACPI: \_SB_.PCI0.LPCB.EC__: Boot DSDT EC used to handle transactions
	ACPI: Interpreter enabled

It kind of makes sense that, if "\" is seen as an EC in the Medion that 
it is not going to work.

             reply index

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-14 19:28 Jan Engelhardt [this message]
2020-02-16  0:32 ` Rafael J. Wysocki
2020-02-16 14:15   ` Jan Engelhardt
2020-02-16 20:49     ` Rafael J. Wysocki
2020-02-17  0:10       ` Jan Engelhardt
2020-02-17 20:23         ` Rafael J. Wysocki

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