Re: [PATCH] HID: hid-sensor-hub: Fix lockdep warning for dynamic callback locks.

[Jonathan Cameron]

On 14/05/14 02:49, Reyad Attiyat wrote:
> Here is a sample of the kernel lockdep warning I got after turingon
> dynamic debugging:
> https://bugzilla.kernel.org/show_bug.cgi?id=73321#c3
>
>
>
> On Tue, May 13, 2014 at 8:03 PM, Reyad Attiyat <reyad.attiyat@xxxxxxxxx> wrote:
> > Changes all dyn_callback_lock spinlocks to spinlocks that disable
> > interrupts. The dynamic callback lock (dyn_callback_lock) must not be
> > interrupted when locked as it is used in an interrupt handler
> > function, sensor_hub_raw_event.
Looks sane to me, but no sign off and Jiri not cc'd.
Would like an ack from Srinivas as well ideally.

Acked-by: Jonathan Cameron <jic23@xxxxxxxxxx>
> > ---
> >   drivers/hid/hid-sensor-hub.c | 31 ++++++++++++++++++-------------
> >   1 file changed, 18 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/hid/hid-sensor-hub.c b/drivers/hid/hid-sensor-hub.c
> > index af8244b..1e1644c 100644
> > --- a/drivers/hid/hid-sensor-hub.c
> > +++ b/drivers/hid/hid-sensor-hub.c
> > @@ -133,10 +133,11 @@ static struct hid_sensor_hub_callbacks
> > *sensor_hub_get_callback(
> >    struct hid_sensor_hub_device **hsdev,
> >    void **priv)
> >   {
> > + unsigned long flags;
> >    struct hid_sensor_hub_callbacks_list *callback;
> >    struct sensor_hub_data *pdata = hid_get_drvdata(hdev);
> >
> > - spin_lock(&pdata->dyn_callback_lock);
> > + spin_lock_irqsave(&pdata->dyn_callback_lock, flags);
> >    list_for_each_entry(callback, &pdata->dyn_callback_list, list)
> >    if (callback->usage_id == usage_id &&
> >    (collection_index >=
> > @@ -145,10 +146,10 @@ static struct hid_sensor_hub_callbacks
> > *sensor_hub_get_callback(
> >    callback->hsdev->end_collection_index)) {
> >    *priv = callback->priv;
> >    *hsdev = callback->hsdev;
> > - spin_unlock(&pdata->dyn_callback_lock);
> > + spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);
> >    return callback->usage_callback;
> >    }
> > - spin_unlock(&pdata->dyn_callback_lock);
> > + spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);
> >
> >    return NULL;
> >   }
> > @@ -157,19 +158,20 @@ int sensor_hub_register_callback(struct
> > hid_sensor_hub_device *hsdev,
> >    u32 usage_id,
> >    struct hid_sensor_hub_callbacks *usage_callback)
> >   {
> > + unsigned long flags;
> >    struct hid_sensor_hub_callbacks_list *callback;
> >    struct sensor_hub_data *pdata = hid_get_drvdata(hsdev->hdev);
> >
> > - spin_lock(&pdata->dyn_callback_lock);
> > + spin_lock_irqsave(&pdata->dyn_callback_lock, flags);
> >    list_for_each_entry(callback, &pdata->dyn_callback_list, list)
> >    if (callback->usage_id == usage_id &&
> >    callback->hsdev == hsdev) {
> > - spin_unlock(&pdata->dyn_callback_lock);
> > + spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);
> >    return -EINVAL;
> >    }
> >    callback = kzalloc(sizeof(*callback), GFP_ATOMIC);
> >    if (!callback) {
> > - spin_unlock(&pdata->dyn_callback_lock);
> > + spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);
> >    return -ENOMEM;
> >    }
> >    callback->hsdev = hsdev;
> > @@ -177,7 +179,7 @@ int sensor_hub_register_callback(struct
> > hid_sensor_hub_device *hsdev,
> >    callback->usage_id = usage_id;
> >    callback->priv = NULL;
> >    list_add_tail(&callback->list, &pdata->dyn_callback_list);
> > - spin_unlock(&pdata->dyn_callback_lock);
> > + spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);
> >
> >    return 0;
> >   }
> > @@ -186,10 +188,11 @@ EXPORT_SYMBOL_GPL(sensor_hub_register_callback);
> >   int sensor_hub_remove_callback(struct hid_sensor_hub_device *hsdev,
> >    u32 usage_id)
> >   {
> > + unsigned long flags;
> >    struct hid_sensor_hub_callbacks_list *callback;
> >    struct sensor_hub_data *pdata = hid_get_drvdata(hsdev->hdev);
> >
> > - spin_lock(&pdata->dyn_callback_lock);
> > + spin_lock_irqsave(&pdata->dyn_callback_lock, flags);
> >    list_for_each_entry(callback, &pdata->dyn_callback_list, list)
> >    if (callback->usage_id == usage_id &&
> >    callback->hsdev == hsdev) {
> > @@ -197,7 +200,7 @@ int sensor_hub_remove_callback(struct
> > hid_sensor_hub_device *hsdev,
> >    kfree(callback);
> >    break;
> >    }
> > - spin_unlock(&pdata->dyn_callback_lock);
> > + spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);
> >
> >    return 0;
> >   }
> > @@ -376,34 +379,36 @@ EXPORT_SYMBOL_GPL(sensor_hub_input_get_attribute_info);
> >   #ifdef CONFIG_PM
> >   static int sensor_hub_suspend(struct hid_device *hdev, pm_message_t message)
> >   {
> > + unsigned long flags;
> >    struct sensor_hub_data *pdata = hid_get_drvdata(hdev);
> >    struct hid_sensor_hub_callbacks_list *callback;
> >
> >    hid_dbg(hdev, " sensor_hub_suspend\n");
> > - spin_lock(&pdata->dyn_callback_lock);
> > + spin_lock_irqsave(&pdata->dyn_callback_lock, flags);
> >    list_for_each_entry(callback, &pdata->dyn_callback_list, list) {
> >    if (callback->usage_callback->suspend)
> >    callback->usage_callback->suspend(
> >    callback->hsdev, callback->priv);
> >    }
> > - spin_unlock(&pdata->dyn_callback_lock);
> > + spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);
> >
> >    return 0;
> >   }
> >
> >   static int sensor_hub_resume(struct hid_device *hdev)
> >   {
> > + unsigned long flags;
> >    struct sensor_hub_data *pdata = hid_get_drvdata(hdev);
> >    struct hid_sensor_hub_callbacks_list *callback;
> >
> >    hid_dbg(hdev, " sensor_hub_resume\n");
> > - spin_lock(&pdata->dyn_callback_lock);
> > + spin_lock_irqsave(&pdata->dyn_callback_lock, flags);
> >    list_for_each_entry(callback, &pdata->dyn_callback_list, list) {
> >    if (callback->usage_callback->resume)
> >    callback->usage_callback->resume(
> >    callback->hsdev, callback->priv);
> >    }
> > - spin_unlock(&pdata->dyn_callback_lock);
> > + spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);
> >
> >    return 0;
> >   }
> > --
> > 1.9.0
> --
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