Commit d6323049 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Wentao Guan
Browse files

intel_idle: Handle older CPUs, which stop the TSC in deeper C states, correctly 

stable inclusion
from stable-v6.6.81
commit 3b7d2d1b42d2b7ea4700173c0d785743c1f84dd4
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IBYZED

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3b7d2d1b42d2b7ea4700173c0d785743c1f84dd4



--------------------------------

commit c157d351460bcf202970e97e611cb6b54a3dd4a4 upstream.

The Intel idle driver is preferred over the ACPI processor idle driver,
but fails to implement the work around for Core2 generation CPUs, where
the TSC stops in C2 and deeper C-states. This causes stalls and boot
delays, when the clocksource watchdog does not catch the unstable TSC
before the CPU goes deep idle for the first time.

The ACPI driver marks the TSC unstable when it detects that the CPU
supports C2 or deeper and the CPU does not have a non-stop TSC.

Add the equivivalent work around to the Intel idle driver to cure that.

Fixes: 18734958 ("intel_idle: Use ACPI _CST for processor models without C-state tables")
Reported-by: default avatarFab Stz <fabstz-it@yahoo.fr>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Tested-by: default avatarFab Stz <fabstz-it@yahoo.fr>
Cc: All applicable <stable@vger.kernel.org>
Closes: https://lore.kernel.org/all/10cf96aa-1276-4bd4-8966-c890377030c3@yahoo.fr
Link: https://patch.msgid.link/87bjupfy7f.ffs@tglx


Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 3b7d2d1b42d2b7ea4700173c0d785743c1f84dd4)
Signed-off-by: default avatarWentao Guan <guanwentao@uniontech.com>
parent a218a319

drivers/idle/intel_idle.c

+4 −0
Original line number Diff line number Diff line
@@ -56,6 +56,7 @@ 
#include <asm/nospec-branch.h>

#include <asm/mwait.h>

#include <asm/msr.h>

#include <asm/tsc.h>

#include <asm/fpu/api.h>



#define INTEL_IDLE_VERSION "0.5.1"
@@ -1673,6 +1674,9 @@ static void __init intel_idle_init_cstates_acpi(struct cpuidle_driver *drv) 
		if (intel_idle_state_needs_timer_stop(state))

			state->flags |= CPUIDLE_FLAG_TIMER_STOP;



		if (cx->type > ACPI_STATE_C1 && !boot_cpu_has(X86_FEATURE_NONSTOP_TSC))

			mark_tsc_unstable("TSC halts in idle");



		state->enter = intel_idle;

		state->enter_s2idle = intel_idle_s2idle;

	}