The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x c157d351460bcf202970e97e611cb6b54a3dd4a4 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025030417-diligence-underpay-794f@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From c157d351460bcf202970e97e611cb6b54a3dd4a4 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner tglx@linutronix.de Date: Tue, 25 Feb 2025 23:37:08 +0100 Subject: [PATCH] intel_idle: Handle older CPUs, which stop the TSC in deeper C states, correctly
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: 18734958e9bf ("intel_idle: Use ACPI _CST for processor models without C-state tables") Reported-by: Fab Stz fabstz-it@yahoo.fr Signed-off-by: Thomas Gleixner tglx@linutronix.de Tested-by: Fab 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: Rafael J. Wysocki rafael.j.wysocki@intel.com
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 118fe1d37c22..0fdb1d1316c4 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -56,6 +56,7 @@ #include <asm/intel-family.h> #include <asm/mwait.h> #include <asm/spec-ctrl.h> +#include <asm/tsc.h> #include <asm/fpu/api.h>
#define INTEL_IDLE_VERSION "0.5.1" @@ -1799,6 +1800,9 @@ 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; }