Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030853AbaGRNSb (ORCPT ); Fri, 18 Jul 2014 09:18:31 -0400 Received: from bband-dyn38.178-41-141.t-com.sk ([178.41.141.38]:17967 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1761530AbaGRNS1 (ORCPT ); Fri, 18 Jul 2014 09:18:27 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Fabio Baltieri , Guenter Roeck , Jiri Slaby Subject: [PATCH 3.12 095/170] hwmon: (ina2xx) Cast to s16 on shunt and current regs Date: Fri, 18 Jul 2014 14:11:40 +0200 Message-Id: X-Mailer: git-send-email 2.0.0 In-Reply-To: <48e8cad86bb1241c08bdaa80db022c25068ff8e0.1405685481.git.jslaby@suse.cz> References: <48e8cad86bb1241c08bdaa80db022c25068ff8e0.1405685481.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Fabio Baltieri 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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: Jiri Slaby --- 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 70a39a8ac016..554f5c3fe5c4 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 */ -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/