Re: [PATCH] iio: gyro: mpu3050: fix sign of raw angular velocity readings
From: Joshua Crofts
Date: Sun Aug 02 2026 - 12:03:38 EST
On Sun, 2 Aug 2026 13:55:40 +0700
Cong Nguyen <congnt264@xxxxxxxxx> wrote:
> The MPU-3050 gyroscope output registers hold 16-bit two's complement
> values; the angular velocity channels are declared with .sign = 's'.
> When mpu3050_read_raw() handles IIO_CHAN_INFO_RAW it reads the register
> via a big-endian regmap_bulk_read() and assigns it with:
>
> *val = be16_to_cpu(raw_val);
>
> be16_to_cpu() yields an unsigned 16-bit quantity, so negative rates
> (bit 15 set) are reported to userspace as large positive integers
> (e.g. -1 becomes 65535) instead of the correct negative value.
>
> Cast to s16 before the assignment, matching the temperature channel a
> few lines above which already handles the sign correctly.
>
LGTM.
Reviewed-by: Joshua Crofts <joshua.crofts1@xxxxxxxxx>
--
Kind regards,
Joshua Crofts