From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rhyland Klein Subject: [PATCH] power_supply: fix return value of get_property Date: Mon, 13 Jun 2016 17:03:41 -0400 Message-ID: <1465851821-1163-1-git-send-email-rklein@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from hqemgate15.nvidia.com ([216.228.121.64]:19801 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161183AbcFMVFw (ORCPT ); Mon, 13 Jun 2016 17:05:52 -0400 Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Sebastian Reichel , Dmitry Eremin-Solenikov , David Woodhouse Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Krzysztof Kozlowski , Rhyland Klein power_supply_get_property() should ideally return -EAGAIN if it is called while the power_supply is being registered. There was no way previously to determine if use_cnt == 0 meant that the power_supply wasn't fully registered yet, or if it had already been unregistered. Add a new boolean to the power_supply struct to simply show if registration is completed. Signed-off-by: Rhyland Klein --- This patch continues what was discussed with the patch "power_supply: power_supply_read_temp only if use_cnt > 0". Looking at the thermal code, it looks like we should indeed return EAGAIN if possible, and since this change is fairly simple, I think it makes sense to do it. drivers/power/power_supply_core.c | 6 +++++- include/linux/power_supply.h | 1 + 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c index b13cd074c52a..a39a47672979 100644 --- a/drivers/power/power_supply_core.c +++ b/drivers/power/power_supply_core.c @@ -491,8 +491,11 @@ int power_supply_get_property(struct power_supply *psy, enum power_supply_property psp, union power_supply_propval *val) { - if (atomic_read(&psy->use_cnt) <= 0) + if (atomic_read(&psy->use_cnt) <= 0) { + if (!psy->initialized) + return -EAGAIN; return -ENODEV; + } return psy->desc->get_property(psy, psp, val); } @@ -775,6 +778,7 @@ __power_supply_register(struct device *parent, if (rc) goto create_triggers_failed; + psy->initialized = true; /* * Update use_cnt after any uevents (most notably from device_add()). * We are here still during driver's probe but diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h index 751061790626..3965503315ef 100644 --- a/include/linux/power_supply.h +++ b/include/linux/power_supply.h @@ -248,6 +248,7 @@ struct power_supply { struct delayed_work deferred_register_work; spinlock_t changed_lock; bool changed; + bool initialized; atomic_t use_cnt; #ifdef CONFIG_THERMAL struct thermal_zone_device *tzd; -- 1.9.1