FAILED: patch "[PATCH] iio: imu: inv_icm42600: stabilized timestamp in interrupt" failed to apply to 5.15-stable tree

FAILED: patch "[PATCH] iio: imu: inv_icm42600: stabilized timestamp in interrupt" failed to apply to 5.15-stable tree

[gregkh]

The patch below does not apply to the 5.15-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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x d7bd473632d07f8a54655c270c0940cc3671c548
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2024061750-such-authentic-441b@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

d7bd473632d0 ("iio: imu: inv_icm42600: stabilized timestamp in interrupt")
bf8367b00c33 ("iio: invensense: fix timestamp glitches when switching frequency")
a1432b5b4f4c ("iio: imu: inv_icm42600: add support of ICM-42686-P")
b58b13f156c0 ("iio: invensense: remove redundant initialization of variable period")
111e1abd0045 ("iio: imu: inv_mpu6050: use the common inv_sensors timestamp module")
0ecc363ccea7 ("iio: make invensense timestamp module generic")
d99ff463ecf6 ("iio: move inv_icm42600 timestamp module in common")
6e9f2d8375cb ("iio: imu: inv_icm42600: make timestamp module chip independent")
269b9d8fafbe ("Merge tag 'iio-for-6.5a' of https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into char-misc-next")

thanks,

greg k-h

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

From d7bd473632d07f8a54655c270c0940cc3671c548 Mon Sep 17 00:00:00 2001
From: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
Date: Wed, 29 May 2024 15:47:17 +0000
Subject: [PATCH] iio: imu: inv_icm42600: stabilized timestamp in interrupt

Use IRQF_ONESHOT flag to ensure the timestamp is not updated in the
hard handler during the thread handler. And compute and use the
effective watermark value that correspond to this first timestamp.

This way we can ensure the timestamp is always corresponding to the
value used by the timestamping mechanism. Otherwise, it is possible
that between FIFO count read and FIFO processing the timestamp is
overwritten in the hard handler.

Fixes: ec74ae9fd37c ("iio: imu: inv_icm42600: add accurate timestamping")
Cc: stable@vger.kernel.org
Signed-off-by: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
Link: https://lore.kernel.org/r/20240529154717.651863-1-inv.git-commit@tdk.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c
index 63b85ec88c13..a8cf74c84c3c 100644
--- a/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c
@@ -222,10 +222,15 @@ int inv_icm42600_buffer_update_watermark(struct inv_icm42600_state *st)
 	latency_accel = period_accel * wm_accel;
 
 	/* 0 value for watermark means that the sensor is turned off */
+	if (wm_gyro == 0 && wm_accel == 0)
+		return 0;
+
 	if (latency_gyro == 0) {
 		watermark = wm_accel;
+		st->fifo.watermark.eff_accel = wm_accel;
 	} else if (latency_accel == 0) {
 		watermark = wm_gyro;
+		st->fifo.watermark.eff_gyro = wm_gyro;
 	} else {
 		/* compute the smallest latency that is a multiple of both */
 		if (latency_gyro <= latency_accel)
@@ -241,6 +246,13 @@ int inv_icm42600_buffer_update_watermark(struct inv_icm42600_state *st)
 		watermark = latency / period;
 		if (watermark < 1)
 			watermark = 1;
+		/* update effective watermark */
+		st->fifo.watermark.eff_gyro = latency / period_gyro;
+		if (st->fifo.watermark.eff_gyro < 1)
+			st->fifo.watermark.eff_gyro = 1;
+		st->fifo.watermark.eff_accel = latency / period_accel;
+		if (st->fifo.watermark.eff_accel < 1)
+			st->fifo.watermark.eff_accel = 1;
 	}
 
 	/* compute watermark value in bytes */
@@ -514,7 +526,7 @@ int inv_icm42600_buffer_fifo_parse(struct inv_icm42600_state *st)
 	/* handle gyroscope timestamp and FIFO data parsing */
 	if (st->fifo.nb.gyro > 0) {
 		ts = &gyro_st->ts;
-		inv_sensors_timestamp_interrupt(ts, st->fifo.nb.gyro,
+		inv_sensors_timestamp_interrupt(ts, st->fifo.watermark.eff_gyro,
 						st->timestamp.gyro);
 		ret = inv_icm42600_gyro_parse_fifo(st->indio_gyro);
 		if (ret)
@@ -524,7 +536,7 @@ int inv_icm42600_buffer_fifo_parse(struct inv_icm42600_state *st)
 	/* handle accelerometer timestamp and FIFO data parsing */
 	if (st->fifo.nb.accel > 0) {
 		ts = &accel_st->ts;
-		inv_sensors_timestamp_interrupt(ts, st->fifo.nb.accel,
+		inv_sensors_timestamp_interrupt(ts, st->fifo.watermark.eff_accel,
 						st->timestamp.accel);
 		ret = inv_icm42600_accel_parse_fifo(st->indio_accel);
 		if (ret)
@@ -577,6 +589,9 @@ int inv_icm42600_buffer_init(struct inv_icm42600_state *st)
 	unsigned int val;
 	int ret;
 
+	st->fifo.watermark.eff_gyro = 1;
+	st->fifo.watermark.eff_accel = 1;
+
 	/*
 	 * Default FIFO configuration (bits 7 to 5)
 	 * - use invalid value
diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.h b/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.h
index 8b85ee333bf8..f6c85daf42b0 100644
--- a/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.h
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.h
@@ -32,6 +32,8 @@ struct inv_icm42600_fifo {
 	struct {
 		unsigned int gyro;
 		unsigned int accel;
+		unsigned int eff_gyro;
+		unsigned int eff_accel;
 	} watermark;
 	size_t count;
 	struct {
diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c
index 96116a68ab29..62fdae530334 100644
--- a/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c
@@ -537,6 +537,7 @@ static int inv_icm42600_irq_init(struct inv_icm42600_state *st, int irq,
 	if (ret)
 		return ret;
 
+	irq_type |= IRQF_ONESHOT;
 	return devm_request_threaded_irq(dev, irq, inv_icm42600_irq_timestamp,
 					 inv_icm42600_irq_handler, irq_type,
 					 "inv_icm42600", st);