Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751461AbdGZVc0 (ORCPT ); Wed, 26 Jul 2017 17:32:26 -0400 Received: from mail-out-2.itc.rwth-aachen.de ([134.130.5.47]:10092 "EHLO mail-out-2.itc.rwth-aachen.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750996AbdGZVcY (ORCPT ); Wed, 26 Jul 2017 17:32:24 -0400 X-IronPort-AV: E=Sophos;i="5.40,416,1496095200"; d="scan'208";a="5712872" From: =?UTF-8?q?Stefan=20Br=C3=BCns?= To: CC: , Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , =?UTF-8?q?Stefan=20Br=C3=BCns?= Subject: [PATCH] iio: adc: ina219: Avoid underflow for sleeping time Date: Wed, 26 Jul 2017 23:32:06 +0200 X-Mailer: git-send-email 2.13.3 MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [77.182.179.36] X-ClientProxiedBy: rwthex-w1-a.rwth-ad.de (2002:8682:1a9c::8682:1a9c) To rwthex-w2-b.rwth-ad.de (2002:8682:1a9f::8682:1a9f) Message-ID: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1027 Lines: 29 Proper support for the INA219 lowered the minimum sampling period from 2*140us to 2*84us. Subtracting 200us later leads to an underflow and an almost infinite udelay later. Using a signed int for the sampling period provides sufficient range (at most 2*8640*1024us), but catches the underflow when comparing with buffer_us. Fixes: 18edac2e22f4 ("iio: adc: Fix integration time/averaging for INA219/220") Signed-off-by: Stefan Brüns --- drivers/iio/adc/ina2xx-adc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c index b0d9e3b80e6d..85b419ea9ba9 100644 --- a/drivers/iio/adc/ina2xx-adc.c +++ b/drivers/iio/adc/ina2xx-adc.c @@ -657,7 +657,7 @@ static int ina2xx_capture_thread(void *data) { struct iio_dev *indio_dev = data; struct ina2xx_chip_info *chip = iio_priv(indio_dev); - unsigned int sampling_us = SAMPLING_PERIOD(chip); + int sampling_us = SAMPLING_PERIOD(chip); int buffer_us; /* -- 2.13.3