From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752347AbcFFQ6T (ORCPT ); Mon, 6 Jun 2016 12:58:19 -0400 Received: from hqemgate15.nvidia.com ([216.228.121.64]:15297 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751217AbcFFQ6S (ORCPT ); Mon, 6 Jun 2016 12:58:18 -0400 X-PGP-Universal: processed; by hqnvupgp07.nvidia.com on Mon, 06 Jun 2016 09:55:13 -0700 From: Rhyland Klein To: Sebastian Reichel , Dmitry Eremin-Solenikov , David Woodhouse CC: , , Jon Hunter , Krzysztof Kozlowski , Rhyland Klein , Subject: [RESEND PATCH v2] power_supply: power_supply_read_temp only if use_cnt > 0 Date: Mon, 6 Jun 2016 12:56:56 -0400 Message-ID: <1465232216-12625-1-git-send-email-rklein@nvidia.com> X-Mailer: git-send-email 1.9.1 X-NVConfidentiality: public MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add check to power_supply_read_temp() to only use the power_supply get_property() callback if the use_cnt is > 0. The use_cnt will be incremented at the end of __power_supply_register, so this will block to case where get_property can be called before the supply is fully registered. This fixes the issue show in the stack below: [ 1.452598] power_supply_read_temp+0x78/0x80 [ 1.458680] thermal_zone_get_temp+0x5c/0x11c [ 1.464765] thermal_zone_device_update+0x34/0xb4 [ 1.471195] thermal_zone_device_register+0x87c/0x8cc [ 1.477974] __power_supply_register+0x364/0x424 [ 1.484317] power_supply_register_no_ws+0x10/0x18 [ 1.490833] bq27xxx_battery_setup+0x10c/0x164 [ 1.497003] bq27xxx_battery_i2c_probe+0xd0/0x1b0 [ 1.503435] i2c_device_probe+0x174/0x240 [ 1.509172] driver_probe_device+0x1fc/0x29c [ 1.515167] __driver_attach+0xa4/0xa8 [ 1.520643] bus_for_each_dev+0x58/0x98 [ 1.526204] driver_attach+0x20/0x28 [ 1.531505] bus_add_driver+0x1c8/0x22c [ 1.537067] driver_register+0x68/0x108 [ 1.542630] i2c_register_driver+0x38/0x7c [ 1.548457] bq27xxx_battery_i2c_driver_init+0x18/0x20 [ 1.555321] do_one_initcall+0x38/0x12c [ 1.560886] kernel_init_freeable+0x148/0x1ec [ 1.566972] kernel_init+0x10/0xfc [ 1.572101] ret_from_fork+0x10/0x40 Cc: stable@vger.kernel.org Signed-off-by: Rhyland Klein --- v2: - Added cc stable - changed return to -EAGAIN in case of use_cnt < 1 - Removed WARNING - return value check added in additional patch: "thermal: helpers: Check return value of get_temp" drivers/power/power_supply_core.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c index 456987c88baa..bbd80631f31e 100644 --- a/drivers/power/power_supply_core.c +++ b/drivers/power/power_supply_core.c @@ -561,11 +561,15 @@ static int power_supply_read_temp(struct thermal_zone_device *tzd, { struct power_supply *psy; union power_supply_propval val; - int ret; + int ret = -EAGAIN; WARN_ON(tzd == NULL); + psy = tzd->devdata; - ret = psy->desc->get_property(psy, POWER_SUPPLY_PROP_TEMP, &val); + + if (atomic_read(&psy->use_cnt) > 0) + ret = psy->desc->get_property(psy, POWER_SUPPLY_PROP_TEMP, + &val); /* Convert tenths of degree Celsius to milli degree Celsius. */ if (!ret) -- 1.9.1