Messages in this thread | | | Date | Tue, 11 Oct 2011 15:06:13 +0800 | Subject | Re: [RESEND PATCH 2/2] PM/runtime: handle ->runtime_suspend failure correctly | From | Ming Lei <> |
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Hi
2011/10/11 Rafael J. Wysocki <rjw@sisk.pl>: > On Sunday, October 09, 2011, tom.leiming@gmail.com wrote: >> From: Ming Lei <ming.lei@canonical.com> >> >> 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?
OK, I will split it into two.
> >> - idle notification for suspend failure has been removed, so update >> comments for it >> >> Signed-off-by: Ming Lei <ming.lei@canonical.com> >> --- >> 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.
The 'goto out' above no_callback will bypass this, won't it?
> To achieve the goal (i.e. avoid notifying the parent if -EAGAIN or > -EBUSY is returned by the callbacks) it would be sufficient to
For all non zero value return from callbacks, the idle notification to its parent should be avoided too.
> 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 >
thanks, -- Ming Lei -- 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/
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