From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752787Ab1JJVio (ORCPT ); Mon, 10 Oct 2011 17:38:44 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:59988 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751552Ab1JJVin (ORCPT ); Mon, 10 Oct 2011 17:38:43 -0400 From: "Rafael J. Wysocki" To: tom.leiming@gmail.com Subject: Re: [RESEND PATCH 2/2] PM/runtime: handle ->runtime_suspend failure correctly Date: Mon, 10 Oct 2011 23:40:57 +0200 User-Agent: KMail/1.13.6 (Linux/3.1.0-rc9+; KDE/4.6.0; x86_64; ; ) Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Ming Lei References: <1318131626-9373-1-git-send-email-tom.leiming@gmail.com> <1318131626-9373-2-git-send-email-tom.leiming@gmail.com> In-Reply-To: <1318131626-9373-2-git-send-email-tom.leiming@gmail.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-2" Content-Transfer-Encoding: 7bit Message-Id: <201110102340.57242.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sunday, October 09, 2011, tom.leiming@gmail.com wrote: > From: Ming Lei > > If ->runtime_suspend returns -EAGAIN or -EBUSY, the device should > still be in ACTIVE state, so it is not needed to send idle notification > to its parent; if ->runtime_suspend returns other fatal failure, it > doesn't make sense to send idle notification to its parent. > > So skip these when failure is returned from ->runtime_suspend, also add > comments for this handling in rpm_suspend. > > This patch also updates comments for rpm_suspend: > > - 'Cancel a pending idle notification' should be put before, also > should be changed as 'Cancel a pending idle notification or > autosuspend/suspend' That should be a different patch I think? > - idle notification for suspend failure has been removed, so update > comments for it > > Signed-off-by: Ming Lei > --- > v1: some minor change on Alan's suggestion > --- > drivers/base/power/runtime.c | 34 +++++++++++++++++++--------------- > 1 files changed, 19 insertions(+), 15 deletions(-) > > diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c > index 441b5a3..e3c6a8f 100644 > --- a/drivers/base/power/runtime.c > +++ b/drivers/base/power/runtime.c > @@ -284,14 +284,17 @@ static int rpm_callback(int (*cb)(struct device *), struct device *dev) > * @dev: Device to suspend. > * @rpmflags: Flag bits. > * > - * Check if the device's runtime PM status allows it to be suspended. If > - * another suspend has been started earlier, either return immediately or wait > - * for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC flags. Cancel a > - * pending idle notification. If the RPM_ASYNC flag is set then queue a > - * suspend request; otherwise run the ->runtime_suspend() callback directly. > - * If a deferred resume was requested while the callback was running then carry > - * it out; otherwise send an idle notification for the device (if the suspend > - * failed) or for its parent (if the suspend succeeded). > + * Check if the device's runtime PM status allows it to be suspended. Cancel > + * a pending idle notification or autosuspend/suspend. If another suspend has > + * been started earlier, either return immediately or wait for it to finish, > + * depending on the RPM_NOWAIT and RPM_ASYNC flags. If the RPM_ASYNC flag is > + * set then queue a suspend request; otherwise run the ->runtime_suspend() > + * callback directly. If ->runtime_suspend returns failure, just cancel > + * pending request and wake up waited tasks, then return immediatelly. > + * After ->runtime_suspend succeeded, if a deferred resume was requested > + * while the callback was running then carry it out; otherwise send an idle > + * notification for its parent (if both ignore_children and irq_safe > + * are not set). > * > * This function must be called under dev->power.lock with interrupts disabled. > */ > @@ -410,15 +413,16 @@ static int rpm_suspend(struct device *dev, int rpmflags) > dev->power.runtime_error = 0; > else > pm_runtime_cancel_pending(dev); > - } else { > + wake_up_all(&dev->power.wait_queue); > + goto out; > + } > no_callback: I don't think the change above is correct. The code below no_callback only should be executed if retval is zero. To achieve the goal (i.e. avoid notifying the parent if -EAGAIN or -EBUSY is returned by the callbacks) it would be sufficient to do parent = NULL along with resetting power.runtime_error. > - __update_runtime_status(dev, RPM_SUSPENDED); > - pm_runtime_deactivate_timer(dev); > + __update_runtime_status(dev, RPM_SUSPENDED); > + pm_runtime_deactivate_timer(dev); > > - if (dev->parent) { > - parent = dev->parent; > - atomic_add_unless(&parent->power.child_count, -1, 0); > - } > + if (dev->parent) { > + parent = dev->parent; > + atomic_add_unless(&parent->power.child_count, -1, 0); > } > wake_up_all(&dev->power.wait_queue); Thanks, Rafael