Messages in this thread |  | | Date | Wed, 6 May 2026 17:32:19 +0100 | | From | Jonathan Cameron <> | | Subject | Re: [PATCH v2] iio: temperature: tsys01: fix broken PROM checksum validation |
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On Tue, 5 May 2026 08:10:24 +0100 Salah Triki <salah.triki@gmail.com> wrote:
> The current implementation of tsys01_crc_valid() incorrectly sums the > first word (n_prom[0]) repeatedly instead of iterating over the 8 words > retrieved from the PROM. This leads to a checksum mismatch and probe > failure on hardware. > > According to the TSYS01 datasheet, the PROM consists of 8 words. A valid > check must iterate through all 8 words to verify the integrity of the > calibration data. The current driver only checks the first word 8 times. > > Note: This fix was identified during a code audit and is based on > datasheet specifications. It has not been tested on real hardware. > > Fixes: 43e53407f680 ("Add tsys01 meas-spec driver support") > Signed-off-by: Salah Triki <salah.triki@gmail.com> Bit of a gamble without testing but seems correct to me so small gamble. Even taken it slow path doesn't really guarantee anyone will happen to test it - so...
Applied to the fixes-togreg branch of iio.git and marked for stable. > --- > Changes in v2: > - Update commit message to clarify that the fix is based on the > datasheet analysis. > - Add a note mentioning that it has not been tested on real hardware. > > drivers/iio/temperature/tsys01.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/iio/temperature/tsys01.c b/drivers/iio/temperature/tsys01.c > index 334bba6fdae6..104dd45598b0 100644 > --- a/drivers/iio/temperature/tsys01.c > +++ b/drivers/iio/temperature/tsys01.c > @@ -119,7 +119,7 @@ static bool tsys01_crc_valid(u16 *n_prom) > u8 sum = 0; > > for (cnt = 0; cnt < TSYS01_PROM_WORDS_NB; cnt++) > - sum += ((n_prom[0] >> 8) + (n_prom[0] & 0xFF)); > + sum += ((n_prom[cnt] >> 8) + (n_prom[cnt] & 0xFF)); > > return (sum == 0); > }
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