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HID: stadia: use open/close to manage workqueue lifecycle

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Override input device open() and close() callbacks to enable and disable
the force-feedback workqueue item synchronously.

When the input device is opened by userspace, call hid_hw_open() and
enable_work(). When it is closed, disable_work_sync() ensures that any
pending or running work item is cancelled/flushed and no further work
items can be scheduled.

In close(), zero out magnitudes and issue a final report to turn off the
rumble motors on the physical controller before shutting down transport
I/O.

Pack strong and weak magnitudes into a single u32 integer using
WRITE_ONCE() and READ_ONCE() for atomic, lockless updates.

This allows eliminating the manual 'removed' boolean flag and spinlock
completely.

Assisted-by: Antigravity:gemini-3.6-flash
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
This commit is contained in:
Dmitry Torokhov
2026-08-03 11:46:34 -07:00
committed by Jiri Kosina
parent 37f6ca4369
commit ce75845b69
1 changed files with 38 additions and 33 deletions
Download Patch File Download Diff File Expand all files Collapse all files

71
drivers/hid/hid-google-stadiaff.c
View File

@@ -17,10 +17,7 @@
struct stadiaff_device {
struct hid_device *hid;
struct hid_report *report;
spinlock_t lock;
bool removed;
uint16_t strong_magnitude;
uint16_t weak_magnitude;
u32 magnitudes;
struct work_struct work;
};
@@ -29,12 +26,10 @@ static void stadiaff_work(struct work_struct *work)
struct stadiaff_device *stadiaff =
container_of(work, struct stadiaff_device, work);
struct hid_field *rumble_field = stadiaff->report->field[0];
unsigned long flags;
u32 mags = READ_ONCE(stadiaff->magnitudes);
spin_lock_irqsave(&stadiaff->lock, flags);
rumble_field->value[0] = stadiaff->strong_magnitude;
rumble_field->value[1] = stadiaff->weak_magnitude;
spin_unlock_irqrestore(&stadiaff->lock, flags);
rumble_field->value[0] = mags & 0xffff;
rumble_field->value[1] = (mags >> 16) & 0xffff;
hid_hw_request(stadiaff->hid, stadiaff->report, HID_REQ_SET_REPORT);
}
@@ -44,19 +39,41 @@ static int stadiaff_play(struct input_dev *dev, void *data,
{
struct hid_device *hid = input_get_drvdata(dev);
struct stadiaff_device *stadiaff = hid_get_drvdata(hid);
unsigned long flags;
u32 mags = (u32)effect->u.rumble.strong_magnitude |
((u32)effect->u.rumble.weak_magnitude << 16);
spin_lock_irqsave(&stadiaff->lock, flags);
if (!stadiaff->removed) {
stadiaff->strong_magnitude = effect->u.rumble.strong_magnitude;
stadiaff->weak_magnitude = effect->u.rumble.weak_magnitude;
schedule_work(&stadiaff->work);
}
spin_unlock_irqrestore(&stadiaff->lock, flags);
WRITE_ONCE(stadiaff->magnitudes, mags);
schedule_work(&stadiaff->work);
return 0;
}
static int stadia_input_open(struct input_dev *dev)
{
struct hid_device *hid = input_get_drvdata(dev);
struct stadiaff_device *stadiaff = hid_get_drvdata(hid);
int error;
error = hid_hw_open(hid);
if (error)
return error;
enable_work(&stadiaff->work);
return 0;
}
static void stadia_input_close(struct input_dev *dev)
{
struct hid_device *hid = input_get_drvdata(dev);
struct stadiaff_device *stadiaff = hid_get_drvdata(hid);
WRITE_ONCE(stadiaff->magnitudes, 0);
stadiaff_work(&stadiaff->work);
disable_work_sync(&stadiaff->work);
hid_hw_close(hid);
}
static int stadiaff_init(struct hid_device *hid)
{
struct stadiaff_device *stadiaff;
@@ -90,11 +107,13 @@ static int stadiaff_init(struct hid_device *hid)
if (error)
return error;
stadiaff->removed = false;
stadiaff->hid = hid;
stadiaff->report = report;
INIT_WORK(&stadiaff->work, stadiaff_work);
spin_lock_init(&stadiaff->lock);
disable_work_sync(&stadiaff->work);
dev->open = stadia_input_open;
dev->close = stadia_input_close;
hid_info(hid, "Force Feedback for Google Stadia controller\n");
@@ -127,19 +146,6 @@ static int stadia_probe(struct hid_device *hdev, const struct hid_device_id *id)
return 0;
}
static void stadia_remove(struct hid_device *hid)
{
struct stadiaff_device *stadiaff = hid_get_drvdata(hid);
unsigned long flags;
spin_lock_irqsave(&stadiaff->lock, flags);
stadiaff->removed = true;
spin_unlock_irqrestore(&stadiaff->lock, flags);
cancel_work_sync(&stadiaff->work);
hid_hw_stop(hid);
}
static const struct hid_device_id stadia_devices[] = {
{ HID_USB_DEVICE(USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_STADIA) },
{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_STADIA) },
@@ -151,7 +157,6 @@ static struct hid_driver stadia_driver = {
.name = "stadia",
.id_table = stadia_devices,
.probe = stadia_probe,
.remove = stadia_remove,
};
module_hid_driver(stadia_driver);