From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764926AbdEWU2G (ORCPT ); Tue, 23 May 2017 16:28:06 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:48238 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031662AbdEWU14 (ORCPT ); Tue, 23 May 2017 16:27:56 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andreas Klinger , Linus Walleij , Matt Ranostay , Jonathan Cameron Subject: [PATCH 4.9 066/164] IIO: bmp280-core.c: fix error in humidity calculation Date: Tue, 23 May 2017 22:08:03 +0200 Message-Id: <20170523200910.042628117@linuxfoundation.org> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170523200907.297534241@linuxfoundation.org> References: <20170523200907.297534241@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andreas Klinger commit ed3730c435f1a9f9559ed7762035d22d8a95adfe upstream. While calculating the compensation of the humidity there are negative values interpreted as unsigned because of unsigned variables used. These values as well as the constants need to be casted to signed as indicated by the documentation of the sensor. Signed-off-by: Andreas Klinger Acked-by: Linus Walleij Reviewed-by: Matt Ranostay Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/pressure/bmp280-core.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) --- a/drivers/iio/pressure/bmp280-core.c +++ b/drivers/iio/pressure/bmp280-core.c @@ -175,11 +175,12 @@ static u32 bmp280_compensate_humidity(st } H6 = sign_extend32(tmp, 7); - var = ((s32)data->t_fine) - 76800; - var = ((((adc_humidity << 14) - (H4 << 20) - (H5 * var)) + 16384) >> 15) - * (((((((var * H6) >> 10) * (((var * H3) >> 11) + 32768)) >> 10) - + 2097152) * H2 + 8192) >> 14); - var -= ((((var >> 15) * (var >> 15)) >> 7) * H1) >> 4; + var = ((s32)data->t_fine) - (s32)76800; + var = ((((adc_humidity << 14) - (H4 << 20) - (H5 * var)) + + (s32)16384) >> 15) * (((((((var * H6) >> 10) + * (((var * (s32)H3) >> 11) + (s32)32768)) >> 10) + + (s32)2097152) * H2 + 8192) >> 14); + var -= ((((var >> 15) * (var >> 15)) >> 7) * (s32)H1) >> 4; return var >> 12; };