forked from mirrors/linux
USB: additional power savings for cdc-acm devices that support remote wakeup
this patch saves power for cdc-acm devices that support remote wakeup while the device is connected. - request needs_remote_wakeup when needed - delayed write while a device is autoresumed - the device is marked busy when appropriate Signed-off-by: Oliver Neukum <oneukum@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Oliver Neukum
Greg Kroah-Hartman
parent
188d636027
commit
11ea859d64
2 changed files with 126 additions and 21 deletions
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@ -159,12 +159,34 @@ static void acm_write_done(struct acm *acm, struct acm_wb *wb)
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spin_lock_irqsave(&acm->write_lock, flags);
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acm->write_ready = 1;
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wb->use = 0;
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acm->transmitting--;
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spin_unlock_irqrestore(&acm->write_lock, flags);
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}
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/*
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* Poke write.
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*
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* the caller is responsible for locking
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*/
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static int acm_start_wb(struct acm *acm, struct acm_wb *wb)
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{
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int rc;
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acm->transmitting++;
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wb->urb->transfer_buffer = wb->buf;
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wb->urb->transfer_dma = wb->dmah;
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wb->urb->transfer_buffer_length = wb->len;
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wb->urb->dev = acm->dev;
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if ((rc = usb_submit_urb(wb->urb, GFP_ATOMIC)) < 0) {
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dbg("usb_submit_urb(write bulk) failed: %d", rc);
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acm_write_done(acm, wb);
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}
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return rc;
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}
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static int acm_write_start(struct acm *acm, int wbn)
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{
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unsigned long flags;
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@ -182,26 +204,31 @@ static int acm_write_start(struct acm *acm, int wbn)
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return 0; /* A white lie */
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}
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wb = &acm->wb[wbn];
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if(acm_wb_is_avail(acm) <= 1)
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acm->write_ready = 0;
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dbg("%s susp_count: %d", __func__, acm->susp_count);
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if (acm->susp_count) {
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acm->old_ready = acm->write_ready;
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acm->delayed_wb = wb;
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acm->write_ready = 0;
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schedule_work(&acm->waker);
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spin_unlock_irqrestore(&acm->write_lock, flags);
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return 0; /* A white lie */
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}
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usb_mark_last_busy(acm->dev);
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if (!acm_wb_is_used(acm, wbn)) {
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spin_unlock_irqrestore(&acm->write_lock, flags);
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return 0;
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}
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wb = &acm->wb[wbn];
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if(acm_wb_is_avail(acm) <= 1)
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acm->write_ready = 0;
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rc = acm_start_wb(acm, wb);
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spin_unlock_irqrestore(&acm->write_lock, flags);
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wb->urb->transfer_buffer = wb->buf;
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wb->urb->transfer_dma = wb->dmah;
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wb->urb->transfer_buffer_length = wb->len;
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wb->urb->dev = acm->dev;
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if ((rc = usb_submit_urb(wb->urb, GFP_ATOMIC)) < 0) {
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dbg("usb_submit_urb(write bulk) failed: %d", rc);
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acm_write_done(acm, wb);
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}
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return rc;
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}
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/*
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* attributes exported through sysfs
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@ -304,6 +331,7 @@ static void acm_ctrl_irq(struct urb *urb)
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break;
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}
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exit:
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usb_mark_last_busy(acm->dev);
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retval = usb_submit_urb (urb, GFP_ATOMIC);
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if (retval)
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err ("%s - usb_submit_urb failed with result %d",
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@ -320,8 +348,11 @@ static void acm_read_bulk(struct urb *urb)
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dbg("Entering acm_read_bulk with status %d", status);
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if (!ACM_READY(acm))
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if (!ACM_READY(acm)) {
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dev_dbg(&acm->data->dev, "Aborting, acm not ready");
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return;
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}
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usb_mark_last_busy(acm->dev);
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if (status)
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dev_dbg(&acm->data->dev, "bulk rx status %d\n", status);
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@ -331,6 +362,7 @@ static void acm_read_bulk(struct urb *urb)
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if (likely(status == 0)) {
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spin_lock(&acm->read_lock);
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acm->processing++;
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list_add_tail(&rcv->list, &acm->spare_read_urbs);
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list_add_tail(&buf->list, &acm->filled_read_bufs);
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spin_unlock(&acm->read_lock);
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@ -343,6 +375,7 @@ static void acm_read_bulk(struct urb *urb)
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/* nevertheless the tasklet must be kicked unconditionally
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so the queue cannot dry up */
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}
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if (likely(!acm->susp_count))
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tasklet_schedule(&acm->urb_task);
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}
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@ -354,16 +387,23 @@ static void acm_rx_tasklet(unsigned long _acm)
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struct acm_ru *rcv;
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unsigned long flags;
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unsigned char throttled;
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dbg("Entering acm_rx_tasklet");
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if (!ACM_READY(acm))
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{
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dbg("acm_rx_tasklet: ACM not ready");
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return;
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}
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spin_lock_irqsave(&acm->throttle_lock, flags);
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throttled = acm->throttle;
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spin_unlock_irqrestore(&acm->throttle_lock, flags);
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if (throttled)
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{
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dbg("acm_rx_tasklet: throttled");
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return;
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}
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next_buffer:
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spin_lock_irqsave(&acm->read_lock, flags);
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@ -403,6 +443,7 @@ static void acm_rx_tasklet(unsigned long _acm)
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while (!list_empty(&acm->spare_read_bufs)) {
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spin_lock_irqsave(&acm->read_lock, flags);
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if (list_empty(&acm->spare_read_urbs)) {
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acm->processing = 0;
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spin_unlock_irqrestore(&acm->read_lock, flags);
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return;
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}
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@ -425,18 +466,23 @@ static void acm_rx_tasklet(unsigned long _acm)
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rcv->urb->transfer_dma = buf->dma;
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rcv->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
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dbg("acm_rx_tasklet: sending urb 0x%p, rcv 0x%p, buf 0x%p", rcv->urb, rcv, buf);
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/* This shouldn't kill the driver as unsuccessful URBs are returned to the
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free-urbs-pool and resubmited ASAP */
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if (usb_submit_urb(rcv->urb, GFP_ATOMIC) < 0) {
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list_add(&buf->list, &acm->spare_read_bufs);
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spin_lock_irqsave(&acm->read_lock, flags);
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if (acm->susp_count || usb_submit_urb(rcv->urb, GFP_ATOMIC) < 0) {
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list_add(&buf->list, &acm->spare_read_bufs);
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list_add(&rcv->list, &acm->spare_read_urbs);
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acm->processing = 0;
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spin_unlock_irqrestore(&acm->read_lock, flags);
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return;
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} else {
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spin_unlock_irqrestore(&acm->read_lock, flags);
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dbg("acm_rx_tasklet: sending urb 0x%p, rcv 0x%p, buf 0x%p", rcv->urb, rcv, buf);
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}
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}
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spin_lock_irqsave(&acm->read_lock, flags);
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acm->processing = 0;
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spin_unlock_irqrestore(&acm->read_lock, flags);
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}
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/* data interface wrote those outgoing bytes */
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@ -463,6 +509,27 @@ static void acm_softint(struct work_struct *work)
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tty_wakeup(acm->tty);
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}
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static void acm_waker(struct work_struct *waker)
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{
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struct acm *acm = container_of(waker, struct acm, waker);
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long flags;
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int rv;
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rv = usb_autopm_get_interface(acm->control);
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if (rv < 0) {
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err("Autopm failure in %s", __func__);
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return;
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}
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if (acm->delayed_wb) {
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acm_start_wb(acm, acm->delayed_wb);
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acm->delayed_wb = NULL;
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}
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spin_lock_irqsave(&acm->write_lock, flags);
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acm->write_ready = acm->old_ready;
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spin_unlock_irqrestore(&acm->write_lock, flags);
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usb_autopm_put_interface(acm->control);
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}
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/*
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* TTY handlers
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*/
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@ -492,6 +559,8 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
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if (usb_autopm_get_interface(acm->control) < 0)
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goto early_bail;
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else
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acm->control->needs_remote_wakeup = 1;
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mutex_lock(&acm->mutex);
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if (acm->used++) {
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@ -509,6 +578,7 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
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if (0 > acm_set_control(acm, acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS) &&
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(acm->ctrl_caps & USB_CDC_CAP_LINE))
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goto full_bailout;
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usb_autopm_put_interface(acm->control);
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INIT_LIST_HEAD(&acm->spare_read_urbs);
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INIT_LIST_HEAD(&acm->spare_read_bufs);
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@ -570,12 +640,14 @@ static void acm_tty_close(struct tty_struct *tty, struct file *filp)
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mutex_lock(&open_mutex);
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if (!--acm->used) {
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if (acm->dev) {
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usb_autopm_get_interface(acm->control);
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acm_set_control(acm, acm->ctrlout = 0);
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usb_kill_urb(acm->ctrlurb);
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for (i = 0; i < ACM_NW; i++)
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usb_kill_urb(acm->wb[i].urb);
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for (i = 0; i < nr; i++)
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usb_kill_urb(acm->ru[i].urb);
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acm->control->needs_remote_wakeup = 0;
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usb_autopm_put_interface(acm->control);
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} else
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acm_tty_unregister(acm);
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@ -987,6 +1059,7 @@ static int acm_probe (struct usb_interface *intf,
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acm->urb_task.func = acm_rx_tasklet;
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acm->urb_task.data = (unsigned long) acm;
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INIT_WORK(&acm->work, acm_softint);
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INIT_WORK(&acm->waker, acm_waker);
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spin_lock_init(&acm->throttle_lock);
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spin_lock_init(&acm->write_lock);
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spin_lock_init(&acm->read_lock);
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@ -1116,6 +1189,7 @@ static int acm_probe (struct usb_interface *intf,
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static void stop_data_traffic(struct acm *acm)
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{
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int i;
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dbg("Entering stop_data_traffic");
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tasklet_disable(&acm->urb_task);
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@ -1128,6 +1202,7 @@ static void stop_data_traffic(struct acm *acm)
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tasklet_enable(&acm->urb_task);
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cancel_work_sync(&acm->work);
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cancel_work_sync(&acm->waker);
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}
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static void acm_disconnect(struct usb_interface *intf)
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@ -1181,8 +1256,27 @@ static void acm_disconnect(struct usb_interface *intf)
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static int acm_suspend(struct usb_interface *intf, pm_message_t message)
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{
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struct acm *acm = usb_get_intfdata(intf);
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int cnt;
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if (acm->susp_count++)
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if (acm->dev->auto_pm) {
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int b;
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spin_lock_irq(&acm->read_lock);
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spin_lock(&acm->write_lock);
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b = acm->processing + acm->transmitting;
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spin_unlock(&acm->write_lock);
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spin_unlock_irq(&acm->read_lock);
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if (b)
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return -EBUSY;
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}
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spin_lock_irq(&acm->read_lock);
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spin_lock(&acm->write_lock);
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cnt = acm->susp_count++;
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spin_unlock(&acm->write_lock);
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spin_unlock_irq(&acm->read_lock);
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if (cnt)
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return 0;
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/*
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we treat opened interfaces differently,
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@ -1201,8 +1295,14 @@ static int acm_resume(struct usb_interface *intf)
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{
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struct acm *acm = usb_get_intfdata(intf);
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int rv = 0;
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int cnt;
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if (--acm->susp_count)
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spin_lock_irq(&acm->read_lock);
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acm->susp_count -= 1;
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cnt = acm->susp_count;
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spin_unlock_irq(&acm->read_lock);
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if (cnt)
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return 0;
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mutex_lock(&acm->mutex);
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@ -107,10 +107,14 @@ struct acm {
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struct list_head filled_read_bufs;
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int write_used; /* number of non-empty write buffers */
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int write_ready; /* write urb is not running */
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int old_ready;
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int processing;
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int transmitting;
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spinlock_t write_lock;
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struct mutex mutex;
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struct usb_cdc_line_coding line; /* bits, stop, parity */
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struct work_struct work; /* work queue entry for line discipline waking up */
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struct work_struct waker;
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struct tasklet_struct urb_task; /* rx processing */
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spinlock_t throttle_lock; /* synchronize throtteling and read callback */
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unsigned int ctrlin; /* input control lines (DCD, DSR, RI, break, overruns) */
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@ -123,6 +127,7 @@ struct acm {
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unsigned char clocal; /* termios CLOCAL */
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unsigned int ctrl_caps; /* control capabilities from the class specific header */
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unsigned int susp_count; /* number of suspended interfaces */
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struct acm_wb *delayed_wb; /* write queued for a device about to be woken */
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};
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#define CDC_DATA_INTERFACE_TYPE 0x0a
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