Re: [PATCH] platform/chrome: sensorhub: Fix dropped timestamp events and log spam

[Tzung-Bi Shih <tzungbi@kernel.org>]

On Tue, Jul 14, 2026 at 06:52:02AM +0000, Tzung-Bi Shih wrote:
> 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.
> 
> Additionally, the firmware only ORs the tablet mode flag [2] onto
> timestamp events.  Because the firmware strictly generates standalone
> timestamps (without other flags like ODR or FLUSH), bypassing the bounds
> check for anything containing the TIMESTAMP flag is safe and avoids
> invalid array access.
> 
> Skip the bounds check for events carrying the
> MOTIONSENSE_SENSOR_FLAG_TIMESTAMP flag.

Please disregard the patch.  We found this just opens another door for
malfunctioned or compromised firmware to access the array `batch_state`
out of bound.  Will fix it in v2.