HID: usbhid: remove custom locking from usbhid_open/close
Now that HID core enforces serialization of transport driver open/close
calls we can remove custom locking from usbhid driver.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index d927fe4..76013eb 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -70,8 +70,6 @@
/*
* Input submission and I/O error handler.
*/
-static DEFINE_MUTEX(hid_open_mut);
-
static void hid_io_error(struct hid_device *hid);
static int hid_submit_out(struct hid_device *hid);
static int hid_submit_ctrl(struct hid_device *hid);
@@ -680,50 +678,48 @@
static int usbhid_open(struct hid_device *hid)
{
struct usbhid_device *usbhid = hid->driver_data;
- int res = 0;
+ int res;
- mutex_lock(&hid_open_mut);
- if (!hid->open++) {
- res = usb_autopm_get_interface(usbhid->intf);
- /* the device must be awake to reliably request remote wakeup */
- if (res < 0) {
- hid->open--;
- res = -EIO;
- goto done;
- }
- usbhid->intf->needs_remote_wakeup = 1;
- set_bit(HID_OPENED, &usbhid->iofl);
- set_bit(HID_IN_POLLING, &usbhid->iofl);
- set_bit(HID_RESUME_RUNNING, &usbhid->iofl);
- res = hid_start_in(hid);
- if (res) {
- if (res != -ENOSPC) {
- hid_io_error(hid);
- res = 0;
- } else {
- /* no use opening if resources are insufficient */
- hid->open--;
- clear_bit(HID_OPENED, &usbhid->iofl);
- if (!(hid->quirks & HID_QUIRK_ALWAYS_POLL))
- clear_bit(HID_IN_POLLING, &usbhid->iofl);
- res = -EBUSY;
- usbhid->intf->needs_remote_wakeup = 0;
- }
- }
- usb_autopm_put_interface(usbhid->intf);
+ if (hid->quirks & HID_QUIRK_ALWAYS_POLL)
+ return 0;
- /*
- * In case events are generated while nobody was listening,
- * some are released when the device is re-opened.
- * Wait 50 msec for the queue to empty before allowing events
- * to go through hid.
- */
- if (res == 0 && !(hid->quirks & HID_QUIRK_ALWAYS_POLL))
- msleep(50);
- clear_bit(HID_RESUME_RUNNING, &usbhid->iofl);
+ res = usb_autopm_get_interface(usbhid->intf);
+ /* the device must be awake to reliably request remote wakeup */
+ if (res < 0)
+ return -EIO;
+
+ usbhid->intf->needs_remote_wakeup = 1;
+
+ set_bit(HID_RESUME_RUNNING, &usbhid->iofl);
+ set_bit(HID_OPENED, &usbhid->iofl);
+ set_bit(HID_IN_POLLING, &usbhid->iofl);
+
+ res = hid_start_in(hid);
+ if (res) {
+ if (res != -ENOSPC) {
+ hid_io_error(hid);
+ res = 0;
+ } else {
+ /* no use opening if resources are insufficient */
+ res = -EBUSY;
+ clear_bit(HID_OPENED, &usbhid->iofl);
+ clear_bit(HID_IN_POLLING, &usbhid->iofl);
+ usbhid->intf->needs_remote_wakeup = 0;
+ }
}
-done:
- mutex_unlock(&hid_open_mut);
+
+ usb_autopm_put_interface(usbhid->intf);
+
+ /*
+ * In case events are generated while nobody was listening,
+ * some are released when the device is re-opened.
+ * Wait 50 msec for the queue to empty before allowing events
+ * to go through hid.
+ */
+ if (res == 0)
+ msleep(50);
+
+ clear_bit(HID_RESUME_RUNNING, &usbhid->iofl);
return res;
}
@@ -731,27 +727,22 @@
{
struct usbhid_device *usbhid = hid->driver_data;
- mutex_lock(&hid_open_mut);
+ if (hid->quirks & HID_QUIRK_ALWAYS_POLL)
+ return;
- /* protecting hid->open to make sure we don't restart
- * data acquistion due to a resumption we no longer
- * care about
+ /*
+ * Make sure we don't restart data acquisition due to
+ * a resumption we no longer care about by avoiding racing
+ * with hid_start_in().
*/
spin_lock_irq(&usbhid->lock);
- if (!--hid->open) {
- if (!(hid->quirks & HID_QUIRK_ALWAYS_POLL))
- clear_bit(HID_IN_POLLING, &usbhid->iofl);
- clear_bit(HID_OPENED, &usbhid->iofl);
- spin_unlock_irq(&usbhid->lock);
- hid_cancel_delayed_stuff(usbhid);
- if (!(hid->quirks & HID_QUIRK_ALWAYS_POLL)) {
- usb_kill_urb(usbhid->urbin);
- usbhid->intf->needs_remote_wakeup = 0;
- }
- } else {
- spin_unlock_irq(&usbhid->lock);
- }
- mutex_unlock(&hid_open_mut);
+ clear_bit(HID_IN_POLLING, &usbhid->iofl);
+ clear_bit(HID_OPENED, &usbhid->iofl);
+ spin_unlock_irq(&usbhid->lock);
+
+ hid_cancel_delayed_stuff(usbhid);
+ usb_kill_urb(usbhid->urbin);
+ usbhid->intf->needs_remote_wakeup = 0;
}
/*