From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johan Hovold Subject: [PATCH 1/2] PM / Runtime: fix autosuspend documentation Date: Mon, 10 Apr 2017 13:38:24 +0200 Message-ID: <20170410113825.17399-1-johan@kernel.org> Return-path: Received: from mail-lf0-f67.google.com ([209.85.215.67]:36358 "EHLO mail-lf0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753163AbdDJLiv (ORCPT ); Mon, 10 Apr 2017 07:38:51 -0400 Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Rafael J. Wysocki" Cc: Len Brown , Pavel Machek , Alan Stern , Kevin Hilman , Tony Lindgren , Ulf Hansson , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold Update the autosuspend documentation which claimed that the autosuspend delay is not taken into account when using the non-autosuspend helper functions, something which is no longer true since commit d66e6db28df3 ("PM / Runtime: Respect autosuspend when idle triggers suspend"). This specifically means that drivers must now disable autosuspend before disabling runtime pm in probe error paths and remove callbacks if pm_runtime_put_sync was being used to suspend the device before returning. (If an idle callback can prevent suspend, pm_runtime_put_sync_suspend must be used instead of pm_runtime_put_sync as before.) Also remove the claim that the autosuspend helpers behave "just like the non-autosuspend counterparts", something which have never really been true as some of the latter use idle notifications. Signed-off-by: Johan Hovold --- Documentation/power/runtime_pm.txt | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt index 64546eb9a16a..56a13b865927 100644 --- a/Documentation/power/runtime_pm.txt +++ b/Documentation/power/runtime_pm.txt @@ -836,9 +836,8 @@ of the non-autosuspend counterparts: Instead of: pm_runtime_put_sync use: pm_runtime_put_sync_autosuspend. Drivers may also continue to use the non-autosuspend helper functions; they -will behave normally, not taking the autosuspend delay into account. -Similarly, if the power.use_autosuspend field isn't set then the autosuspend -helper functions will behave just like the non-autosuspend counterparts. +will behave normally, which means sometimes taking the autosuspend delay into +account (see pm_runtime_idle). Under some circumstances a driver or subsystem may want to prevent a device from autosuspending immediately, even though the usage counter is zero and the -- 2.12.2