Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:41010 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751152AbdFSPSl (ORCPT ); Mon, 19 Jun 2017 11:18:41 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Abhiram Balasubramanian , Eva Rachel Retuya , Jonathan Cameron Subject: [PATCH 4.11 38/78] staging: iio: tsl2x7x_core: Fix standard deviation calculation Date: Mon, 19 Jun 2017 23:15:38 +0800 Message-Id: <20170619151030.841200937@linuxfoundation.org> In-Reply-To: <20170619151029.408399976@linuxfoundation.org> References: <20170619151029.408399976@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eva Rachel Retuya commit cf6c77323a96fc40309cc8a4921ef206cccdd961 upstream. Standard deviation is calculated as the square root of the variance where variance is the mean of sample_sum and length. Correct the computation of statP->stddev in accordance to the proper calculation. Fixes: 3c97c08b5735 ("staging: iio: add TAOS tsl2x7x driver") Reported-by: Abhiram Balasubramanian Signed-off-by: Eva Rachel Retuya Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/staging/iio/light/tsl2x7x_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/staging/iio/light/tsl2x7x_core.c +++ b/drivers/staging/iio/light/tsl2x7x_core.c @@ -854,7 +854,7 @@ void tsl2x7x_prox_calculate(int *data, i tmp = data[i] - statP->mean; sample_sum += tmp * tmp; } - statP->stddev = int_sqrt((long)sample_sum) / length; + statP->stddev = int_sqrt((long)sample_sum / length); } /**