1 files changed, 143 insertions, 34 deletions

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index c3201affa0b6..95ae6377d7e5 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -159,12 +159,34 @@ static void acm_write_done(struct acm *acm, struct acm_wb *wb)
         spin_lock_irqsave(&acm->write_lock, flags);
         acm->write_ready = 1;
         wb->use = 0;
+        acm->transmitting--;
         spin_unlock_irqrestore(&acm->write_lock, flags);
 }
 
 /*
  * Poke write.
+ *
+ * the caller is responsible for locking
  */
+
+static int acm_start_wb(struct acm *acm, struct acm_wb *wb)
+{
+        int rc;
+
+        acm->transmitting++;
+
+        wb->urb->transfer_buffer = wb->buf;
+        wb->urb->transfer_dma = wb->dmah;
+        wb->urb->transfer_buffer_length = wb->len;
+        wb->urb->dev = acm->dev;
+
+        if ((rc = usb_submit_urb(wb->urb, GFP_ATOMIC)) < 0) {
+                dbg("usb_submit_urb(write bulk) failed: %d", rc);
+                acm_write_done(acm, wb);
+        }
+        return rc;
+}
+
 static int acm_write_start(struct acm *acm, int wbn)
 {
         unsigned long flags;
@@ -182,26 +204,31 @@ static int acm_write_start(struct acm *acm, int wbn)
                 return 0;       /* A white lie */
         }
 
+        wb = &acm->wb[wbn];
+        if(acm_wb_is_avail(acm) <= 1)
+                acm->write_ready = 0;
+
+        dbg("%s susp_count: %d", __func__, acm->susp_count);
+        if (acm->susp_count) {
+                acm->old_ready = acm->write_ready;
+                acm->delayed_wb = wb;
+                acm->write_ready = 0;
+                schedule_work(&acm->waker);
+                spin_unlock_irqrestore(&acm->write_lock, flags);
+                return 0;       /* A white lie */
+        }
+        usb_mark_last_busy(acm->dev);
+
         if (!acm_wb_is_used(acm, wbn)) {
                 spin_unlock_irqrestore(&acm->write_lock, flags);
                 return 0;
         }
-        wb = &acm->wb[wbn];
 
-        if(acm_wb_is_avail(acm) <= 1)
-                acm->write_ready = 0;
+        rc = acm_start_wb(acm, wb);
         spin_unlock_irqrestore(&acm->write_lock, flags);
 
-        wb->urb->transfer_buffer = wb->buf;
-        wb->urb->transfer_dma = wb->dmah;
-        wb->urb->transfer_buffer_length = wb->len;
-        wb->urb->dev = acm->dev;
-
-        if ((rc = usb_submit_urb(wb->urb, GFP_ATOMIC)) < 0) {
-                dbg("usb_submit_urb(write bulk) failed: %d", rc);
-                acm_write_done(acm, wb);
-        }
         return rc;
+
 }
 /*
  * attributes exported through sysfs
@@ -304,6 +331,7 @@ static void acm_ctrl_irq(struct urb *urb)
                         break;
         }
 exit:
+        usb_mark_last_busy(acm->dev);
         retval = usb_submit_urb (urb, GFP_ATOMIC);
         if (retval)
                 err ("%s - usb_submit_urb failed with result %d",
@@ -320,8 +348,11 @@ static void acm_read_bulk(struct urb *urb)
 
         dbg("Entering acm_read_bulk with status %d", status);
 
-        if (!ACM_READY(acm))
+        if (!ACM_READY(acm)) {
+                dev_dbg(&acm->data->dev, "Aborting, acm not ready");
                 return;
+        }
+        usb_mark_last_busy(acm->dev);
 
         if (status)
                 dev_dbg(&acm->data->dev, "bulk rx status %d\n", status);
@@ -331,6 +362,7 @@ static void acm_read_bulk(struct urb *urb)
 
         if (likely(status == 0)) {
                 spin_lock(&acm->read_lock);
+                acm->processing++;
                 list_add_tail(&rcv->list, &acm->spare_read_urbs);
                 list_add_tail(&buf->list, &acm->filled_read_bufs);
                 spin_unlock(&acm->read_lock);
@@ -343,7 +375,8 @@ static void acm_read_bulk(struct urb *urb)
                 /* nevertheless the tasklet must be kicked unconditionally
                 so the queue cannot dry up */
         }
-        tasklet_schedule(&acm->urb_task);
+        if (likely(!acm->susp_count))
+                tasklet_schedule(&acm->urb_task);
 }
 
 static void acm_rx_tasklet(unsigned long _acm)
@@ -354,16 +387,23 @@ static void acm_rx_tasklet(unsigned long _acm)
         struct acm_ru *rcv;
         unsigned long flags;
         unsigned char throttled;
+
         dbg("Entering acm_rx_tasklet");
 
         if (!ACM_READY(acm))
+        {
+                dbg("acm_rx_tasklet: ACM not ready");
                 return;
+        }
 
         spin_lock_irqsave(&acm->throttle_lock, flags);
         throttled = acm->throttle;
         spin_unlock_irqrestore(&acm->throttle_lock, flags);
         if (throttled)
+        {
+                dbg("acm_rx_tasklet: throttled");
                 return;
+        }
 
 next_buffer:
         spin_lock_irqsave(&acm->read_lock, flags);
@@ -403,6 +443,7 @@ urbs:
         while (!list_empty(&acm->spare_read_bufs)) {
                 spin_lock_irqsave(&acm->read_lock, flags);
                 if (list_empty(&acm->spare_read_urbs)) {
+                        acm->processing = 0;
                         spin_unlock_irqrestore(&acm->read_lock, flags);
                         return;
                 }
@@ -425,18 +466,23 @@ urbs:
                 rcv->urb->transfer_dma = buf->dma;
                 rcv->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 
-                dbg("acm_rx_tasklet: sending urb 0x%p, rcv 0x%p, buf 0x%p", rcv->urb, rcv, buf);
-
                 /* This shouldn't kill the driver as unsuccessful URBs are returned to the
                    free-urbs-pool and resubmited ASAP */
-                if (usb_submit_urb(rcv->urb, GFP_ATOMIC) < 0) {
+                spin_lock_irqsave(&acm->read_lock, flags);
+                if (acm->susp_count || usb_submit_urb(rcv->urb, GFP_ATOMIC) < 0) {
                         list_add(&buf->list, &acm->spare_read_bufs);
-                        spin_lock_irqsave(&acm->read_lock, flags);
                         list_add(&rcv->list, &acm->spare_read_urbs);
+                        acm->processing = 0;
                         spin_unlock_irqrestore(&acm->read_lock, flags);
                         return;
+                } else {
+                        spin_unlock_irqrestore(&acm->read_lock, flags);
+                        dbg("acm_rx_tasklet: sending urb 0x%p, rcv 0x%p, buf 0x%p", rcv->urb, rcv, buf);
                 }
         }
+        spin_lock_irqsave(&acm->read_lock, flags);
+        acm->processing = 0;
+        spin_unlock_irqrestore(&acm->read_lock, flags);
 }
 
 /* data interface wrote those outgoing bytes */
@@ -463,6 +509,27 @@ static void acm_softint(struct work_struct *work)
         tty_wakeup(acm->tty);
 }
 
+static void acm_waker(struct work_struct *waker)
+{
+        struct acm *acm = container_of(waker, struct acm, waker);
+        long flags;
+        int rv;
+
+        rv = usb_autopm_get_interface(acm->control);
+        if (rv < 0) {
+                err("Autopm failure in %s", __func__);
+                return;
+        }
+        if (acm->delayed_wb) {
+                acm_start_wb(acm, acm->delayed_wb);
+                acm->delayed_wb = NULL;
+        }
+        spin_lock_irqsave(&acm->write_lock, flags);
+        acm->write_ready = acm->old_ready;
+        spin_unlock_irqrestore(&acm->write_lock, flags);
+        usb_autopm_put_interface(acm->control);
+}
+
 /*
  * TTY handlers
  */
@@ -492,6 +559,8 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
 
         if (usb_autopm_get_interface(acm->control) < 0)
                 goto early_bail;
+        else
+                acm->control->needs_remote_wakeup = 1;
 
         mutex_lock(&acm->mutex);
         if (acm->used++) {
@@ -509,6 +578,7 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
         if (0 > acm_set_control(acm, acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS) &&
             (acm->ctrl_caps & USB_CDC_CAP_LINE))
                 goto full_bailout;
+        usb_autopm_put_interface(acm->control);
 
         INIT_LIST_HEAD(&acm->spare_read_urbs);
         INIT_LIST_HEAD(&acm->spare_read_bufs);
@@ -570,12 +640,14 @@ static void acm_tty_close(struct tty_struct *tty, struct file *filp)
         mutex_lock(&open_mutex);
         if (!--acm->used) {
                 if (acm->dev) {
+                        usb_autopm_get_interface(acm->control);
                         acm_set_control(acm, acm->ctrlout = 0);
                         usb_kill_urb(acm->ctrlurb);
                         for (i = 0; i < ACM_NW; i++)
                                 usb_kill_urb(acm->wb[i].urb);
                         for (i = 0; i < nr; i++)
                                 usb_kill_urb(acm->ru[i].urb);
+                        acm->control->needs_remote_wakeup = 0;
                         usb_autopm_put_interface(acm->control);
                 } else
                         acm_tty_unregister(acm);
@@ -766,7 +838,7 @@ static void acm_tty_set_termios(struct tty_struct *tty, struct ktermios *termios
  * USB probe and disconnect routines.
  */
 
-/* Little helper: write buffers free */
+/* Little helpers: write/read buffers free */
 static void acm_write_buffers_free(struct acm *acm)
 {
         int i;
@@ -777,6 +849,15 @@ static void acm_write_buffers_free(struct acm *acm)
         }
 }
 
+static void acm_read_buffers_free(struct acm *acm)
+{
+        struct usb_device *usb_dev = interface_to_usbdev(acm->control);
+        int i, n = acm->rx_buflimit;
+
+        for (i = 0; i < n; i++)
+                usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);
+}
+
 /* Little helper: write buffers allocate */
 static int acm_write_buffers_alloc(struct acm *acm)
 {
@@ -987,6 +1068,7 @@ skip_normal_probe:
         acm->urb_task.func = acm_rx_tasklet;
         acm->urb_task.data = (unsigned long) acm;
         INIT_WORK(&acm->work, acm_softint);
+        INIT_WORK(&acm->waker, acm_waker);
         spin_lock_init(&acm->throttle_lock);
         spin_lock_init(&acm->write_lock);
         spin_lock_init(&acm->read_lock);
@@ -1098,8 +1180,7 @@ alloc_fail8:
         for (i = 0; i < ACM_NW; i++)
                 usb_free_urb(acm->wb[i].urb);
 alloc_fail7:
-        for (i = 0; i < num_rx_buf; i++)
-                usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);
+        acm_read_buffers_free(acm);
         for (i = 0; i < num_rx_buf; i++)
                 usb_free_urb(acm->ru[i].urb);
         usb_free_urb(acm->ctrlurb);
@@ -1116,6 +1197,7 @@ alloc_fail:
 static void stop_data_traffic(struct acm *acm)
 {
         int i;
+        dbg("Entering stop_data_traffic");
 
         tasklet_disable(&acm->urb_task);
 
@@ -1128,21 +1210,16 @@ static void stop_data_traffic(struct acm *acm)
         tasklet_enable(&acm->urb_task);
 
         cancel_work_sync(&acm->work);
+        cancel_work_sync(&acm->waker);
 }
 
 static void acm_disconnect(struct usb_interface *intf)
 {
         struct acm *acm = usb_get_intfdata(intf);
         struct usb_device *usb_dev = interface_to_usbdev(intf);
-        int i;
-
-        if (!acm || !acm->dev) {
-                dbg("disconnect on nonexisting interface");
-                return;
-        }
 
         mutex_lock(&open_mutex);
-        if (!usb_get_intfdata(intf)) {
+        if (!acm || !acm->dev) {
                 mutex_unlock(&open_mutex);
                 return;
         }
@@ -1161,10 +1238,10 @@ static void acm_disconnect(struct usb_interface *intf)
 
         acm_write_buffers_free(acm);
         usb_buffer_free(usb_dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
-        for (i = 0; i < acm->rx_buflimit; i++)
-                usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);
+        acm_read_buffers_free(acm);
 
-        usb_driver_release_interface(&acm_driver, intf == acm->control ? acm->data : intf);
+        usb_driver_release_interface(&acm_driver, intf == acm->control ?
+                                        acm->data : acm->control);
 
         if (!acm->used) {
                 acm_tty_unregister(acm);
@@ -1178,11 +1255,31 @@ static void acm_disconnect(struct usb_interface *intf)
                 tty_hangup(acm->tty);
 }
 
+#ifdef CONFIG_PM
 static int acm_suspend(struct usb_interface *intf, pm_message_t message)
 {
         struct acm *acm = usb_get_intfdata(intf);
+        int cnt;
+
+        if (acm->dev->auto_pm) {
+                int b;
+
+                spin_lock_irq(&acm->read_lock);
+                spin_lock(&acm->write_lock);
+                b = acm->processing + acm->transmitting;
+                spin_unlock(&acm->write_lock);
+                spin_unlock_irq(&acm->read_lock);
+                if (b)
+                        return -EBUSY;
+        }
+
+        spin_lock_irq(&acm->read_lock);
+        spin_lock(&acm->write_lock);
+        cnt = acm->susp_count++;
+        spin_unlock(&acm->write_lock);
+        spin_unlock_irq(&acm->read_lock);
 
-        if (acm->susp_count++)
+        if (cnt)
                 return 0;
         /*
         we treat opened interfaces differently,
@@ -1201,15 +1298,21 @@ static int acm_resume(struct usb_interface *intf)
 {
         struct acm *acm = usb_get_intfdata(intf);
         int rv = 0;
+        int cnt;
+
+        spin_lock_irq(&acm->read_lock);
+        acm->susp_count -= 1;
+        cnt = acm->susp_count;
+        spin_unlock_irq(&acm->read_lock);
 
-        if (--acm->susp_count)
+        if (cnt)
                 return 0;
 
         mutex_lock(&acm->mutex);
         if (acm->used) {
                 rv = usb_submit_urb(acm->ctrlurb, GFP_NOIO);
                 if (rv < 0)
-                goto err_out;
+                        goto err_out;
 
                 tasklet_schedule(&acm->urb_task);
         }
@@ -1218,6 +1321,8 @@ err_out:
         mutex_unlock(&acm->mutex);
         return rv;
 }
+
+#endif /* CONFIG_PM */
 /*
  * USB driver structure.
  */
@@ -1273,10 +1378,14 @@ static struct usb_driver acm_driver = {
         .name =         "cdc_acm",
         .probe =        acm_probe,
         .disconnect =   acm_disconnect,
+#ifdef CONFIG_PM
         .suspend =      acm_suspend,
         .resume =       acm_resume,
+#endif
         .id_table =     acm_ids,
+#ifdef CONFIG_PM
         .supports_autosuspend = 1,
+#endif
 };
 
 /*