# --- T2-COPYRIGHT-BEGIN ---
# t2/package/*/linux/hotfix-x86-coretemp.patch
# Copyright (C) 2026 The T2 SDE Project
# SPDX-License-Identifier: GPL-2.0 or patched project license
# --- T2-COPYRIGHT-END ---

hwmon/coretemp: fix temperature stuck at 0 for the first 5 minutes after boot

temp_data is kzalloc'd, so last_updated starts at 0. show_temp() only
re-reads IA32_THERM_STATUS when time_after(jiffies, last_updated + HZ),
which stays false on 32-bit until jiffies wraps past INITIAL_JIFFIES
(-300*HZ) - i.e. for the first 5 minutes of uptime. Until then
temp*_input reports the kzalloc'd 0. Observed on an Intel Atom Z530
(Nokia Booklet 3G): MSR readout valid at 35 C while sysfs returned 0,
recovering at exactly uptime 300s. Backdate last_updated so the first
read always updates.

Signed-off-by: René Rebe <rene@exactco.de>

--- linux-7.1/drivers/hwmon/coretemp.c.orig
+++ linux-7.1/drivers/hwmon/coretemp.c
@@ -520,6 +520,8 @@ init_temp_data(struct platform_data *pda
 	tdata->cpu = cpu;
 	tdata->cpu_core_id = topology_core_id(cpu);
 	tdata->attr_size = MAX_CORE_ATTRS;
+	/* 0 would keep time_after() false until INITIAL_JIFFIES */
+	tdata->last_updated = jiffies - HZ - 1;
 	mutex_init(&tdata->update_lock);
 	return tdata;
 }