]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - drivers/usb/class/cdc-acm.c
usb: cdc-acm: stop dropping tx buffers
[linux-2.6-omap-h63xx.git] / drivers / usb / class / cdc-acm.c
index c3201affa0b6f99c17ff6d28c71e3cd08adb58c6..a9dd28f446d8f1fad580eda15ff2c75dc49afc75 100644 (file)
@@ -144,11 +144,6 @@ static int acm_wb_is_avail(struct acm *acm)
        return n;
 }
 
-static inline int acm_wb_is_used(struct acm *acm, int wbn)
-{
-       return acm->wb[wbn].use;
-}
-
 /*
  * Finish write.
  */
@@ -157,51 +152,62 @@ static void acm_write_done(struct acm *acm, struct acm_wb *wb)
        unsigned long flags;
 
        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;
-       struct acm_wb *wb;
+       struct acm_wb *wb = &acm->wb[wbn];
        int rc;
 
        spin_lock_irqsave(&acm->write_lock, flags);
        if (!acm->dev) {
+               wb->use = 0;
                spin_unlock_irqrestore(&acm->write_lock, flags);
                return -ENODEV;
        }
 
-       if (!acm->write_ready) {
+       dbg("%s susp_count: %d", __func__, acm->susp_count);
+       if (acm->susp_count) {
+               acm->delayed_wb = wb;
+               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 +310,7 @@ 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 +327,11 @@ 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 +341,7 @@ 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 +354,8 @@ 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 +366,23 @@ 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 +422,7 @@ 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 +445,23 @@ 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 +488,23 @@ 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);
+       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;
+       }
+       usb_autopm_put_interface(acm->control);
+}
+
 /*
  * TTY handlers
  */
@@ -492,6 +534,8 @@ 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 +553,7 @@ 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 +615,14 @@ 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);
@@ -625,7 +672,7 @@ static int acm_tty_write_room(struct tty_struct *tty)
         * Do not let the line discipline to know that we have a reserve,
         * or it might get too enthusiastic.
         */
-       return (acm->write_ready && acm_wb_is_avail(acm)) ? acm->writesize : 0;
+       return acm_wb_is_avail(acm) ? acm->writesize : 0;
 }
 
 static int acm_tty_chars_in_buffer(struct tty_struct *tty)
@@ -660,13 +707,16 @@ static void acm_tty_unthrottle(struct tty_struct *tty)
        tasklet_schedule(&acm->urb_task);
 }
 
-static void acm_tty_break_ctl(struct tty_struct *tty, int state)
+static int acm_tty_break_ctl(struct tty_struct *tty, int state)
 {
        struct acm *acm = tty->driver_data;
+       int retval;
        if (!ACM_READY(acm))
-               return;
-       if (acm_send_break(acm, state ? 0xffff : 0))
+               return -EINVAL;
+       retval = acm_send_break(acm, state ? 0xffff : 0);
+       if (retval < 0)
                dbg("send break failed");
+       return retval;
 }
 
 static int acm_tty_tiocmget(struct tty_struct *tty, struct file *file)
@@ -766,7 +816,7 @@ 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 +827,15 @@ 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)
 {
@@ -987,11 +1046,11 @@ 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);
        mutex_init(&acm->mutex);
-       acm->write_ready = 1;
        acm->rx_endpoint = usb_rcvbulkpipe(usb_dev, epread->bEndpointAddress);
 
        buf = usb_buffer_alloc(usb_dev, ctrlsize, GFP_KERNEL, &acm->ctrl_dma);
@@ -1023,9 +1082,11 @@ skip_normal_probe:
                rcv->instance = acm;
        }
        for (i = 0; i < num_rx_buf; i++) {
-               struct acm_rb *buf = &(acm->rb[i]);
+               struct acm_rb *rb = &(acm->rb[i]);
 
-               if (!(buf->base = usb_buffer_alloc(acm->dev, readsize, GFP_KERNEL, &buf->dma))) {
+               rb->base = usb_buffer_alloc(acm->dev, readsize,
+                               GFP_KERNEL, &rb->dma);
+               if (!rb->base) {
                        dev_dbg(&intf->dev, "out of memory (read bufs usb_buffer_alloc)\n");
                        goto alloc_fail7;
                }
@@ -1087,6 +1148,7 @@ skip_countries:
        acm_set_line(acm, &acm->line);
 
        usb_driver_claim_interface(&acm_driver, data_interface, acm);
+       usb_set_intfdata(data_interface, acm);
 
        usb_get_intf(control_interface);
        tty_register_device(acm_tty_driver, minor, &control_interface->dev);
@@ -1098,8 +1160,7 @@ 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 +1177,7 @@ alloc_fail:
 static void stop_data_traffic(struct acm *acm)
 {
        int i;
+       dbg("Entering stop_data_traffic");
 
        tasklet_disable(&acm->urb_task);
 
@@ -1128,24 +1190,19 @@ 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");
+       /* sibling interface is already cleaning up */
+       if (!acm)
                return;
-       }
 
        mutex_lock(&open_mutex);
-       if (!usb_get_intfdata(intf)) {
-               mutex_unlock(&open_mutex);
-               return;
-       }
        if (acm->country_codes){
                device_remove_file(&acm->control->dev,
                                &dev_attr_wCountryCodes);
@@ -1161,10 +1218,10 @@ 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 +1235,31 @@ 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 +1278,21 @@ 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 +1301,8 @@ err_out:
        mutex_unlock(&acm->mutex);
        return rv;
 }
+
+#endif /* CONFIG_PM */
 /*
  * USB driver structure.
  */
@@ -1273,10 +1358,14 @@ 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
 };
 
 /*