diff options
| -rw-r--r-- | drivers/usb/class/cdc-acm.c | 29 | ||||
| -rw-r--r-- | include/linux/usb/cdc.h | 7 |
2 files changed, 25 insertions, 11 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 98199628e39..023cf5d45a9 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -326,10 +326,16 @@ static void acm_rx_tasklet(unsigned long _acm) struct tty_struct *tty = acm->tty; struct acm_ru *rcv; unsigned long flags; - int i = 0; + unsigned char throttled; dbg("Entering acm_rx_tasklet"); - if (!ACM_READY(acm) || acm->throttle) + if (!ACM_READY(acm)) + return; + + spin_lock(&acm->throttle_lock); + throttled = acm->throttle; + spin_unlock(&acm->throttle_lock); + if (throttled) return; next_buffer: @@ -346,22 +352,20 @@ next_buffer: dbg("acm_rx_tasklet: procesing buf 0x%p, size = %d", buf, buf->size); tty_buffer_request_room(tty, buf->size); - if (!acm->throttle) + spin_lock(&acm->throttle_lock); + throttled = acm->throttle; + spin_unlock(&acm->throttle_lock); + if (!throttled) tty_insert_flip_string(tty, buf->base, buf->size); tty_flip_buffer_push(tty); - spin_lock(&acm->throttle_lock); - if (acm->throttle) { - dbg("Throtteling noticed"); - memmove(buf->base, buf->base + i, buf->size - i); - buf->size -= i; - spin_unlock(&acm->throttle_lock); + if (throttled) { + dbg("Throttling noticed"); spin_lock_irqsave(&acm->read_lock, flags); list_add(&buf->list, &acm->filled_read_bufs); spin_unlock_irqrestore(&acm->read_lock, flags); return; } - spin_unlock(&acm->throttle_lock); spin_lock_irqsave(&acm->read_lock, flags); list_add(&buf->list, &acm->spare_read_bufs); @@ -467,7 +471,8 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp) goto bail_out; } - if (0 > acm_set_control(acm, acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS)) + if (0 > acm_set_control(acm, acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS) && + (acm->ctrl_caps & USB_CDC_CAP_LINE)) goto full_bailout; INIT_LIST_HEAD(&acm->spare_read_urbs); @@ -480,6 +485,8 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp) list_add(&(acm->rb[i].list), &acm->spare_read_bufs); } + acm->throttle = 0; + tasklet_schedule(&acm->urb_task); done: diff --git a/include/linux/usb/cdc.h b/include/linux/usb/cdc.h index ba617c37245..956edf3bbec 100644 --- a/include/linux/usb/cdc.h +++ b/include/linux/usb/cdc.h @@ -73,6 +73,13 @@ struct usb_cdc_acm_descriptor { __u8 bmCapabilities; } __attribute__ ((packed)); +/* capabilities from 5.2.3.3 */ + +#define USB_CDC_COMM_FEATURE 0x01 +#define USB_CDC_CAP_LINE 0x02 +#define USB_CDC_CAP_BRK 0x04 +#define USB_CDC_CAP_NOTIFY 0x08 + /* "Union Functional Descriptor" from CDC spec 5.2.3.8 */ struct usb_cdc_union_desc { __u8 bLength; |