FAILED: patch "[PATCH] hwmon: (tmp102) Fix jiffies wraparound in conversion-ready check" failed to apply to 6.6-stable tree

FAILED: patch "[PATCH] hwmon: (tmp102) Fix jiffies wraparound in conversion-ready check" failed to apply to 6.6-stable tree

[Sasha Levin]

The patch below does not apply to the 6.6-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-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 56c1d32323e773b8b927316f8beeae9238576335
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '20261107053022-failed-6.6-56c1d32323e7@kernel.org' --subject-prefix 'PATCH 6.6.y' 'HEAD^..'

Thanks,
Sasha

------------------ original commit in Linus's tree ------------------

From 56c1d32323e773b8b927316f8beeae9238576335 Mon Sep 17 00:00:00 2001
From: Tom Verdonck <tom.verdonck@inspiral.be>
Date: Fri, 25 Sep 2026 20:23:22 +0200
Subject: [PATCH] hwmon: (tmp102) Fix jiffies wraparound in conversion-ready
 check

tmp102 records a one-shot deadline in ->ready_time at probe (and resume)
and, on every temperature read, refuses the read with -EAGAIN while
time_before(jiffies, ready_time) is true, in order to skip the first
~35 ms conversion.

->ready_time is an unsigned long compared with time_before(), whose
signed difference is only meaningful while the two values are within
LONG_MAX jiffies of each other. Because ->ready_time is set once and
never refreshed, jiffies keeps advancing away from it, and after 2^31
jiffies the difference flips sign. On a 32-bit HZ=100 kernel that
happens ~248.5 days after boot: time_before() then permanently reports
"not ready" and the driver returns -EAGAIN on every read, without ever
touching the sensor, until the next reboot.

Store the deadline as a 64-bit jiffies value and compare it with
get_jiffies_64()/time_before64(), which does not wrap in any practical
uptime.

Fixes: 3d8f7a89a197 ("hwmon: (tmp102) Improve handling of initial read delay")
Cc: stable@vger.kernel.org
Signed-off-by: Tom Verdonck <tom.verdonck@inspiral.be>
Link: https://patch.msgid.link/2952f070f82913aea96eec25d28008d3b9058656.1790358356.git.tom.verdonck@inspiral.be
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/tmp102.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
index 50a8b050d8da1..8c8463ddb6c45 100644
--- a/drivers/hwmon/tmp102.c
+++ b/drivers/hwmon/tmp102.c
@@ -58,7 +58,7 @@ struct tmp102 {
 	const char *label;
 	struct regmap *regmap;
 	u16 config_orig;
-	unsigned long ready_time;
+	u64 ready_time;
 	u16 sample_time;
 };
 
@@ -106,7 +106,7 @@ static int tmp102_read_temp(struct device *dev, u32 attr, long *val)
 	switch (attr) {
 	case hwmon_temp_input:
 		/* Is it too early to return a conversion ? */
-		if (time_before(jiffies, tmp102->ready_time)) {
+		if (time_before64(get_jiffies_64(), tmp102->ready_time)) {
 			dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__);
 			return -EAGAIN;
 		}
@@ -354,7 +354,7 @@ static int tmp102_probe(struct i2c_client *client)
 	 * Mark that we are not ready with data until the first
 	 * conversion is complete
 	 */
-	tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);
+	tmp102->ready_time = get_jiffies_64() + msecs_to_jiffies(CONVERSION_TIME_MS);
 
 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 							 tmp102,
@@ -387,7 +387,7 @@ static int tmp102_resume(struct device *dev)
 	err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,
 				 TMP102_CONF_SD, 0);
 
-	tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);
+	tmp102->ready_time = get_jiffies_64() + msecs_to_jiffies(CONVERSION_TIME_MS);
 
 	return err;
 }
-- 
2.53.0

[PATCH 6.6.y] hwmon: (tmp102) Fix jiffies wraparound in conversion-ready check

[Sasha Levin]

From: Tom Verdonck <tom.verdonck@inspiral.be>

[ Upstream commit 56c1d32323e773b8b927316f8beeae9238576335 ]

tmp102 records a one-shot deadline in ->ready_time at probe (and resume)
and, on every temperature read, refuses the read with -EAGAIN while
time_before(jiffies, ready_time) is true, in order to skip the first
~35 ms conversion.

->ready_time is an unsigned long compared with time_before(), whose
signed difference is only meaningful while the two values are within
LONG_MAX jiffies of each other. Because ->ready_time is set once and
never refreshed, jiffies keeps advancing away from it, and after 2^31
jiffies the difference flips sign. On a 32-bit HZ=100 kernel that
happens ~248.5 days after boot: time_before() then permanently reports
"not ready" and the driver returns -EAGAIN on every read, without ever
touching the sensor, until the next reboot.

Store the deadline as a 64-bit jiffies value and compare it with
get_jiffies_64()/time_before64(), which does not wrap in any practical
uptime.

Fixes: 3d8f7a89a197 ("hwmon: (tmp102) Improve handling of initial read delay")
Cc: stable@vger.kernel.org
Signed-off-by: Tom Verdonck <tom.verdonck@inspiral.be>
Link: https://patch.msgid.link/2952f070f82913aea96eec25d28008d3b9058656.1790358356.git.tom.verdonck@inspiral.be
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
[ sashal: adjusted context because temperature reads are handled by tmp102_read() instead of tmp102_read_temp() ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/hwmon/tmp102.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
index 2506c78590afe..be4ce0be9b7f2 100644
--- a/drivers/hwmon/tmp102.c
+++ b/drivers/hwmon/tmp102.c
@@ -54,7 +54,7 @@
 struct tmp102 {
 	struct regmap *regmap;
 	u16 config_orig;
-	unsigned long ready_time;
+	u64 ready_time;
 };
 
 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */
@@ -79,7 +79,7 @@ static int tmp102_read(struct device *dev, enum hwmon_sensor_types type,
 	switch (attr) {
 	case hwmon_temp_input:
 		/* Is it too early to return a conversion ? */
-		if (time_before(jiffies, tmp102->ready_time)) {
+		if (time_before64(get_jiffies_64(), tmp102->ready_time)) {
 			dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__);
 			return -EAGAIN;
 		}
@@ -245,7 +245,7 @@ static int tmp102_probe(struct i2c_client *client)
 	 * Mark that we are not ready with data until the first
 	 * conversion is complete
 	 */
-	tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);
+	tmp102->ready_time = get_jiffies_64() + msecs_to_jiffies(CONVERSION_TIME_MS);
 
 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 							 tmp102,
@@ -278,7 +278,7 @@ static int tmp102_resume(struct device *dev)
 	err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,
 				 TMP102_CONF_SD, 0);
 
-	tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);
+	tmp102->ready_time = get_jiffies_64() + msecs_to_jiffies(CONVERSION_TIME_MS);
 
 	return err;
 }
-- 
2.53.0