On Monday, July 06, 2015 01:01:18 PM Felipe Balbi wrote:
> on a first call to dev_pm_attach_wake_irq(), if it
> fails, it will leave dev->power.wakeirq set to a
> dangling pointer. Instead, let's clear it to make
> sure a subsequent call to dev_pm_attach_wake_irq()
> has chance to succeed.
>
> Cc: Tony Lindgren <tmlind@xxxxxxxxxxx>
> Signed-off-by: Felipe Balbi <balbi@xxxxxx>
> ---
> drivers/base/power/wakeirq.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/base/power/wakeirq.c b/drivers/base/power/wakeirq.c
> index 7470004ca810..394d250a1ad8 100644
> --- a/drivers/base/power/wakeirq.c
> +++ b/drivers/base/power/wakeirq.c
> @@ -50,9 +50,16 @@ static int dev_pm_attach_wake_irq(struct device *dev, int irq,
>
> err = device_wakeup_attach_irq(dev, wirq);
> if (err)
> - return err;
> + goto err_cleanup;
>
> return 0;
> +
> +err_cleanup:
> + spin_lock_irqsave(&dev->power.lock, flags);
> + dev->power.wakeirq = NULL;
> + spin_unlock_irqrestore(&dev->power.lock, flags);
> +
> + return err;
> }
Too many labels for me and the fact that acquiring of the lock again in the error
patch doesn't look good.
However, we can do the entire device_wakeup_attach_irq() under the lock (after
removing the locking from it), because we're its only caller.
So what about the below instead (build-tested only)?
Rafael
---
drivers/base/power/wakeirq.c | 12 +++++-------
drivers/base/power/wakeup.c | 31 ++++++++++---------------------
2 files changed, 15 insertions(+), 28 deletions(-)
Index: linux-pm/drivers/base/power/wakeirq.c
===================================================================
--- linux-pm.orig/drivers/base/power/wakeirq.c
+++ linux-pm/drivers/base/power/wakeirq.c
@@ -45,14 +45,12 @@ static int dev_pm_attach_wake_irq(struct
return -EEXIST;
}
- dev->power.wakeirq = wirq;
- spin_unlock_irqrestore(&dev->power.lock, flags);
-
err = device_wakeup_attach_irq(dev, wirq);
- if (err)
- return err;
+ if (!err)
+ dev->power.wakeirq = wirq;
- return 0;
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+ return err;
}
/**
@@ -105,10 +103,10 @@ void dev_pm_clear_wake_irq(struct device
return;
spin_lock_irqsave(&dev->power.lock, flags);
+ device_wakeup_detach_irq(dev);
dev->power.wakeirq = NULL;
spin_unlock_irqrestore(&dev->power.lock, flags);
- device_wakeup_detach_irq(dev);
if (wirq->dedicated_irq)
free_irq(wirq->irq, wirq);
kfree(wirq);
Index: linux-pm/drivers/base/power/wakeup.c
===================================================================
--- linux-pm.orig/drivers/base/power/wakeup.c
+++ linux-pm/drivers/base/power/wakeup.c
@@ -281,32 +281,25 @@ EXPORT_SYMBOL_GPL(device_wakeup_enable);
* Attach a device wakeirq to the wakeup source so the device
* wake IRQ can be configured automatically for suspend and
* resume.
+ *
+ * Call under the device's power.lock lock.
*/
int device_wakeup_attach_irq(struct device *dev,
struct wake_irq *wakeirq)
{
struct wakeup_source *ws;
- int ret = 0;
- spin_lock_irq(&dev->power.lock);
ws = dev->power.wakeup;
if (!ws) {
dev_err(dev, "forgot to call call device_init_wakeup?\n");
- ret = -EINVAL;
- goto unlock;
+ return -EINVAL;
}
- if (ws->wakeirq) {
- ret = -EEXIST;
- goto unlock;
- }
+ if (ws->wakeirq)
+ return -EEXIST;
ws->wakeirq = wakeirq;
-
-unlock:
- spin_unlock_irq(&dev->power.lock);
-
- return ret;
+ return 0;
}
/**
@@ -314,20 +307,16 @@ unlock:
* @dev: Device to handle
*
* Removes a device wakeirq from the wakeup source.
+ *
+ * Call under the device's power.lock lock.
*/
void device_wakeup_detach_irq(struct device *dev)
{
struct wakeup_source *ws;
- spin_lock_irq(&dev->power.lock);
ws = dev->power.wakeup;
- if (!ws)
- goto unlock;
-
- ws->wakeirq = NULL;
-
-unlock:
- spin_unlock_irq(&dev->power.lock);
+ if (ws)
+ ws->wakeirq = NULL;
}
/**
--
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