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

From: Jonathan Cameron
Date: Sat May 24 2014 - 06:30:26 EST


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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