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authorWoody Suwalski <wsuwalski@gmail.com>2022-02-09 16:05:09 -0500
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2022-02-16 18:17:16 +0100
commitbfe55a1f7fd6bfede16078bf04c6250fbca11588 (patch)
tree545cb8633f3d7d852e52af9fb6c0e00babe7f56b /drivers/acpi/processor_idle.c
parent754e0b0e35608ed5206d6a67a791563c631cec07 (diff)
downloadlinux-bfe55a1f7fd6bfede16078bf04c6250fbca11588.tar.gz
ACPI: processor: idle: fix lockup regression on 32-bit ThinkPad T40
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@amd.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@gmail.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Cc: 5.16+ <stable@vger.kernel.org> # 5.16+ [ rjw: New subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/processor_idle.c')
-rw-r--r--drivers/acpi/processor_idle.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 86560a28751b..f8e9fa82cb9b 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -96,6 +96,11 @@ static const struct dmi_system_id processor_power_dmi_table[] = {
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},
{},
};