5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Tzung-Bi Shih <tzungbi@kernel.org>
commit 9a3f43b30373c61477d0d3ab52946c05f9492bf9 upstream.
Commit 833740a2333c ("platform/chrome: sensorhub: Bound the EC-reported
sensor number") evaluated the `sensor_num` against the bounds limit even
for timestamp events. A timestamp event typically has a `sensor_num` of
0xff [1], causing the driver to flag it as invalid and skip to the next
event.
As a result, we'd see a flooding of "Invalid sensor number 255 from EC"
warning logs and these timestamp events were being dropped.
Move the bounds-check into cros_ec_sensor_ring_process_event() and
evaluate it only after standalone timestamp events have already been
processed and returned early.
[1] https://crrev.com/219ca6ef82ba266da788b673ee4ad50bd3ea1285/common/motion_sense_fifo.c#427
Fixes: 833740a2333c ("platform/chrome: sensorhub: Bound the EC-reported sensor number")
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Link: https://lore.kernel.org/r/20260715024454.4127571-1-tzungbi@kernel.org (local)
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/platform/chrome/cros_ec_sensorhub_ring.c | 27 ++++++++++++-----------
1 file changed, 15 insertions(+), 12 deletions(-)
--- a/drivers/platform/chrome/cros_ec_sensorhub_ring.c
+++ b/drivers/platform/chrome/cros_ec_sensorhub_ring.c
@@ -436,6 +436,21 @@ cros_ec_sensor_ring_process_event(struct
fifo_timestamp,
*current_timestamp,
now);
+
+ /*
+ * A standalone timestamp event typically has a sensor_num of
+ * 0xff. Return early here to prevent it from hitting the
+ * bounds check below and spamming the logs.
+ */
+ return false;
+ }
+
+ /* Skip event if sensor_num from EC is out of bounds. */
+ if (in->sensor_num >= sensorhub->sensor_num) {
+ dev_warn_ratelimited(sensorhub->dev,
+ "Invalid sensor number %u from EC\n",
+ in->sensor_num);
+ return false;
}
if (in->flags & MOTIONSENSE_SENSOR_FLAG_ODR) {@@ -463,10 +478,6 @@ cros_ec_sensor_ring_process_event(struct
return true;
}
- if (in->flags & MOTIONSENSE_SENSOR_FLAG_TIMESTAMP)
- /* If we just have a timestamp, skip this entry. */
- return false;
-
/* Regular sample */
out->sensor_id = in->sensor_num;
trace_cros_ec_sensorhub_data(in->sensor_num,
@@ -851,14 +862,6 @@ static void cros_ec_sensorhub_ring_handl
for (in = sensorhub->resp->fifo_read.data, j = 0;
j < number_data; j++, in++) {
- /* Skip event if sensor_num from EC is out of bounds. */
- if (in->sensor_num >= sensorhub->sensor_num) {
- dev_warn_ratelimited(sensorhub->dev,
- "Invalid sensor number %u from EC\n",
- in->sensor_num);
- continue;
- }
-
if (cros_ec_sensor_ring_process_event(
sensorhub, fifo_info,
fifo_timestamp,