USB: cdc-acm: remove redundant usb_mark_last_busy

[firefly-linux-kernel-4.4.55.git] / drivers / usb / class / cdc-acm.c

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index eddeba61a88c87adfe9bdd777993532c253f59cd..8f654ce52570677732364164f17dc5c65ea04e3f 100644 (file)
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -416,19 +416,21 @@ static void acm_read_bulk_callback(struct urb *urb)
                dev_dbg(&acm->data->dev, "%s - disconnected\n", __func__);
                return;
        }
-       usb_mark_last_busy(acm->dev);
 
        if (urb->status) {
                dev_dbg(&acm->data->dev, "%s - non-zero urb status: %d\n",
                                                        __func__, urb->status);
                return;
        }
+
+       usb_mark_last_busy(acm->dev);
+
        acm_process_read_urb(acm, urb);
 
        /* throttle device if requested by tty */
        spin_lock_irqsave(&acm->read_lock, flags);
        acm->throttled = acm->throttle_req;
-       if (!acm->throttled && !acm->susp_count) {
+       if (!acm->throttled) {
                spin_unlock_irqrestore(&acm->read_lock, flags);
                acm_submit_read_urb(acm, rb->index, GFP_ATOMIC);
        } else {
@@ -593,29 +595,33 @@ static void acm_port_shutdown(struct tty_port *port)
 
        dev_dbg(&acm->control->dev, "%s\n", __func__);
 
-       mutex_lock(&acm->mutex);
-       if (!acm->disconnected) {
-               usb_autopm_get_interface(acm->control);
-               acm_set_control(acm, acm->ctrlout = 0);
+       acm_set_control(acm, acm->ctrlout = 0);
 
-               for (;;) {
-                       urb = usb_get_from_anchor(&acm->delayed);
-                       if (!urb)
-                               break;
-                       wb = urb->context;
-                       wb->use = 0;
-                       usb_autopm_put_interface_async(acm->control);
-               }
+       /*
+        * Need to grab write_lock to prevent race with resume, but no need to
+        * hold it due to the tty-port initialised flag.
+        */
+       spin_lock_irq(&acm->write_lock);
+       spin_unlock_irq(&acm->write_lock);
 
-               usb_kill_urb(acm->ctrlurb);
-               for (i = 0; i < ACM_NW; i++)
-                       usb_kill_urb(acm->wb[i].urb);
-               for (i = 0; i < acm->rx_buflimit; i++)
-                       usb_kill_urb(acm->read_urbs[i]);
-               acm->control->needs_remote_wakeup = 0;
-               usb_autopm_put_interface(acm->control);
+       usb_autopm_get_interface_no_resume(acm->control);
+       acm->control->needs_remote_wakeup = 0;
+       usb_autopm_put_interface(acm->control);
+
+       for (;;) {
+               urb = usb_get_from_anchor(&acm->delayed);
+               if (!urb)
+                       break;
+               wb = urb->context;
+               wb->use = 0;
+               usb_autopm_put_interface_async(acm->control);
        }
-       mutex_unlock(&acm->mutex);
+
+       usb_kill_urb(acm->ctrlurb);
+       for (i = 0; i < ACM_NW; i++)
+               usb_kill_urb(acm->wb[i].urb);
+       for (i = 0; i < acm->rx_buflimit; i++)
+               usb_kill_urb(acm->read_urbs[i]);
 }
 
 static void acm_tty_cleanup(struct tty_struct *tty)
@@ -684,7 +690,6 @@ static int acm_tty_write(struct tty_struct *tty,
                spin_unlock_irqrestore(&acm->write_lock, flags);
                return count;
        }
-       usb_mark_last_busy(acm->dev);
 
        stat = acm_start_wb(acm, wb);
        spin_unlock_irqrestore(&acm->write_lock, flags);
@@ -1544,18 +1549,15 @@ static int acm_suspend(struct usb_interface *intf, pm_message_t message)
        struct acm *acm = usb_get_intfdata(intf);
        int cnt;
 
-       spin_lock_irq(&acm->read_lock);
-       spin_lock(&acm->write_lock);
+       spin_lock_irq(&acm->write_lock);
        if (PMSG_IS_AUTO(message)) {
                if (acm->transmitting) {
-                       spin_unlock(&acm->write_lock);
-                       spin_unlock_irq(&acm->read_lock);
+                       spin_unlock_irq(&acm->write_lock);
                        return -EBUSY;
                }
        }
        cnt = acm->susp_count++;
-       spin_unlock(&acm->write_lock);
-       spin_unlock_irq(&acm->read_lock);
+       spin_unlock_irq(&acm->write_lock);
 
        if (cnt)
                return 0;
@@ -1571,8 +1573,7 @@ static int acm_resume(struct usb_interface *intf)
        struct urb *urb;
        int rv = 0;
 
-       spin_lock_irq(&acm->read_lock);
-       spin_lock(&acm->write_lock);
+       spin_lock_irq(&acm->write_lock);
 
        if (--acm->susp_count)
                goto out;
@@ -1598,8 +1599,7 @@ static int acm_resume(struct usb_interface *intf)
                rv = acm_submit_read_urbs(acm, GFP_ATOMIC);
        }
 out:
-       spin_unlock(&acm->write_lock);
-       spin_unlock_irq(&acm->read_lock);
+       spin_unlock_irq(&acm->write_lock);
 
        return rv;
 }