From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from saturn.retrosnub.co.uk ([178.18.118.26]:39380 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933621Ab3AIVQZ (ORCPT ); Wed, 9 Jan 2013 16:16:25 -0500 Message-ID: <50EDDE25.4040101@kernel.org> Date: Wed, 09 Jan 2013 21:16:21 +0000 From: Jonathan Cameron MIME-Version: 1.0 To: Lars-Peter Clausen CC: Jonathan Cameron , linux-iio@vger.kernel.org Subject: Re: [PATCH 1/7] staging:iio:adis16080: Perform sign extension References: <1357740079-12326-1-git-send-email-lars@metafoo.de> <50EDCE61.8000001@kernel.org> <50EDD472.7000604@metafoo.de> In-Reply-To: <50EDD472.7000604@metafoo.de> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 01/09/2013 08:34 PM, Lars-Peter Clausen wrote: > On 01/09/2013 09:09 PM, Jonathan Cameron wrote: >> On 01/09/2013 02:01 PM, Lars-Peter Clausen wrote: >>> The adis16080 reports sample values in twos complement. So we need to perform a >>> sign extension on the result, otherwise negative values will be reported >>> incorrectly as large positive values. >>> >>> Signed-off-by: Lars-Peter Clausen >> Added to fixes-togreg branch of iio.git >>> >>> --- >>> This one should go into 3.8 if possible, the rest of the series is for 3.9 >>> --- >>> drivers/staging/iio/gyro/adis16080_core.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/staging/iio/gyro/adis16080_core.c b/drivers/staging/iio/gyro/adis16080_core.c >>> index 3525a68..149ff99 100644 >>> --- a/drivers/staging/iio/gyro/adis16080_core.c >>> +++ b/drivers/staging/iio/gyro/adis16080_core.c >>> @@ -69,7 +69,7 @@ static int adis16080_spi_read(struct iio_dev *indio_dev, >>> ret = spi_read(st->us, st->buf, 2); >>> >>> if (ret == 0) >>> - *val = ((st->buf[0] & 0xF) << 8) | st->buf[1]; >>> + *val = sign_extend32(12, ((st->buf[0] & 0xF) << 8) | st->buf[1]); >>> mutex_unlock(&st->buf_lock); >>> > > Sorry, now that I look at it from a distance: This is completely wrong... > It needs to be, > > sign_extend32((st->buf[0] & 0xF) << 8) | st->buf[1], 11); > > Sorry again, > - Lars > Fixed up. Hadn't pushed out yet anyway so only messing in my local tree.