From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759641AbaGOWFD (ORCPT ); Tue, 15 Jul 2014 18:05:03 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:54557 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759462AbaGOVgn (ORCPT ); Tue, 15 Jul 2014 17:36:43 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Fabio Baltieri , Guenter Roeck , Kamal Mostafa Subject: [PATCH 3.13 132/198] hwmon: (ina2xx) Cast to s16 on shunt and current regs Date: Tue, 15 Jul 2014 14:30:02 -0700 Message-Id: <1405459868-15089-133-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1405459868-15089-1-git-send-email-kamal@canonical.com> References: <1405459868-15089-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11.5 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Fabio Baltieri commit c0214f98943b1fe43f7be61b7782b0c8f0836f28 upstream. All devices supported by ina2xx are bidirectional and report the measured shunt voltage and power values as a signed 16 bit, but the current driver implementation caches all registers as u16, leading to an incorrect sign extension when reporting to userspace in ina2xx_get_value(). This patch fixes the problem by casting the signed registers to s16. Tested on an INA219. Signed-off-by: Fabio Baltieri Signed-off-by: Guenter Roeck Signed-off-by: Kamal Mostafa --- drivers/hwmon/ina2xx.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c index 93d26e8..bfd3f3e 100644 --- a/drivers/hwmon/ina2xx.c +++ b/drivers/hwmon/ina2xx.c @@ -148,7 +148,8 @@ static int ina2xx_get_value(struct ina2xx_data *data, u8 reg) switch (reg) { case INA2XX_SHUNT_VOLTAGE: - val = DIV_ROUND_CLOSEST(data->regs[reg], + /* signed register */ + val = DIV_ROUND_CLOSEST((s16)data->regs[reg], data->config->shunt_div); break; case INA2XX_BUS_VOLTAGE: @@ -160,8 +161,8 @@ static int ina2xx_get_value(struct ina2xx_data *data, u8 reg) val = data->regs[reg] * data->config->power_lsb; break; case INA2XX_CURRENT: - /* LSB=1mA (selected). Is in mA */ - val = data->regs[reg]; + /* signed register, LSB=1mA (selected), in mA */ + val = (s16)data->regs[reg]; break; default: /* programmer goofed */ -- 1.9.1