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Message-Id: <20220418121200.682225683@linuxfoundation.org>
Date: Mon, 18 Apr 2022 14:10:28 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Woody Suwalski <wsuwalski@...il.com>,
Hans de Goede <hdegoede@...hat.com>,
"Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
"Limonciello, Mario" <Mario.Limonciello@....com>
Subject: [PATCH 5.15 008/189] ACPI: processor: idle: fix lockup regression on 32-bit ThinkPad T40
From: Woody Suwalski <wsuwalski@...il.com>
commit bfe55a1f7fd6bfede16078bf04c6250fbca11588 upstream.
Add and ACPI idle power level limit for 32-bit ThinkPad T40.
There is a regression on T40 introduced by commit d6b88ce2, starting
with kernel 5.16:
commit d6b88ce2eb9d2698eb24451eb92c0a1649b17bb1
Author: Richard Gong <richard.gong@....com>
Date: Wed Sep 22 08:31:16 2021 -0500
ACPI: processor idle: Allow playing dead in C3 state
The above patch is trying to enter C3 state during init, what is causing
a T40 system freeze. I have not found a similar issue on any other of my
32-bit machines.
The fix is to add another exception to the processor_power_dmi_table[] list.
As a result the dmesg shows as expected:
[2.155398] ACPI: IBM ThinkPad T40 detected - limiting to C2 max_cstate. Override with "processor.max_cstate=9"
[2.155404] ACPI: processor limited to max C-state 2
The fix is trivial and affects only vintage T40 systems.
Fixes: d6b88ce2eb9d ("CPI: processor idle: Allow playing dead in C3 state")
Signed-off-by: Woody Suwalski <wsuwalski@...il.com>
Reviewed-by: Hans de Goede <hdegoede@...hat.com>
Cc: 5.16+ <stable@...r.kernel.org> # 5.16+
[ rjw: New subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Cc: "Limonciello, Mario" <Mario.Limonciello@....com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
drivers/acpi/processor_idle.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -95,6 +95,11 @@ static const struct dmi_system_id proces
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
(void *)1},
+ /* T40 can not handle C3 idle state */
+ { set_max_cstate, "IBM ThinkPad T40", {
+ DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "23737CU")},
+ (void *)2},
{},
};
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