diff options
| -rw-r--r-- | drivers/usb/gadget/u_serial.c | 54 |
1 files changed, 40 insertions, 14 deletions
diff --git a/drivers/usb/gadget/u_serial.c b/drivers/usb/gadget/u_serial.c index 01e5354a4c20..40f7716b31fc 100644 --- a/drivers/usb/gadget/u_serial.c +++ b/drivers/usb/gadget/u_serial.c @@ -105,11 +105,15 @@ struct gs_port { wait_queue_head_t close_wait; /* wait for last close */ struct list_head read_pool; + int read_started; + int read_allocated; struct list_head read_queue; unsigned n_read; struct tasklet_struct push; struct list_head write_pool; + int write_started; + int write_allocated; struct gs_buf port_write_buf; wait_queue_head_t drain_wait; /* wait while writes drain */ @@ -363,6 +367,9 @@ __acquires(&port->port_lock) struct usb_request *req; int len; + if (port->write_started >= QUEUE_SIZE) + break; + req = list_entry(pool->next, struct usb_request, list); len = gs_send_packet(port, req->buf, in->maxpacket); if (len == 0) { @@ -397,6 +404,8 @@ __acquires(&port->port_lock) break; } + port->write_started++; + /* abort immediately after disconnect */ if (!port->port_usb) break; @@ -418,7 +427,6 @@ __acquires(&port->port_lock) { struct list_head *pool = &port->read_pool; struct usb_ep *out = port->port_usb->out; - unsigned started = 0; while (!list_empty(pool)) { struct usb_request *req; @@ -430,6 +438,9 @@ __acquires(&port->port_lock) if (!tty) break; + if (port->read_started >= QUEUE_SIZE) + break; + req = list_entry(pool->next, struct usb_request, list); list_del(&req->list); req->length = out->maxpacket; @@ -447,13 +458,13 @@ __acquires(&port->port_lock) list_add(&req->list, pool); break; } - started++; + port->read_started++; /* abort immediately after disconnect */ if (!port->port_usb) break; } - return started; + return port->read_started; } /* @@ -535,6 +546,7 @@ static void gs_rx_push(unsigned long _port) } recycle: list_move(&req->list, &port->read_pool); + port->read_started--; } /* Push from tty to ldisc; without low_latency set this is handled by @@ -587,6 +599,7 @@ static void gs_write_complete(struct usb_ep *ep, struct usb_request *req) spin_lock(&port->port_lock); list_add(&req->list, &port->write_pool); + port->write_started--; switch (req->status) { default: @@ -608,7 +621,8 @@ static void gs_write_complete(struct usb_ep *ep, struct usb_request *req) spin_unlock(&port->port_lock); } -static void gs_free_requests(struct usb_ep *ep, struct list_head *head) +static void gs_free_requests(struct usb_ep *ep, struct list_head *head, + int *allocated) { struct usb_request *req; @@ -616,25 +630,31 @@ static void gs_free_requests(struct usb_ep *ep, struct list_head *head) req = list_entry(head->next, struct usb_request, list); list_del(&req->list); gs_free_req(ep, req); + if (allocated) + (*allocated)--; } } static int gs_alloc_requests(struct usb_ep *ep, struct list_head *head, - void (*fn)(struct usb_ep *, struct usb_request *)) + void (*fn)(struct usb_ep *, struct usb_request *), + int *allocated) { int i; struct usb_request *req; + int n = allocated ? QUEUE_SIZE - *allocated : QUEUE_SIZE; /* Pre-allocate up to QUEUE_SIZE transfers, but if we can't * do quite that many this time, don't fail ... we just won't * be as speedy as we might otherwise be. */ - for (i = 0; i < QUEUE_SIZE; i++) { + for (i = 0; i < n; i++) { req = gs_alloc_req(ep, ep->maxpacket, GFP_ATOMIC); if (!req) return list_empty(head) ? -ENOMEM : 0; req->complete = fn; list_add_tail(&req->list, head); + if (allocated) + (*allocated)++; } return 0; } @@ -661,14 +681,15 @@ static int gs_start_io(struct gs_port *port) * configurations may use different endpoints with a given port; * and high speed vs full speed changes packet sizes too. */ - status = gs_alloc_requests(ep, head, gs_read_complete); + status = gs_alloc_requests(ep, head, gs_read_complete, + &port->read_allocated); if (status) return status; status = gs_alloc_requests(port->port_usb->in, &port->write_pool, - gs_write_complete); + gs_write_complete, &port->write_allocated); if (status) { - gs_free_requests(ep, head); + gs_free_requests(ep, head, &port->read_allocated); return status; } @@ -680,8 +701,9 @@ static int gs_start_io(struct gs_port *port) if (started) { tty_wakeup(port->port_tty); } else { - gs_free_requests(ep, head); - gs_free_requests(port->port_usb->in, &port->write_pool); + gs_free_requests(ep, head, &port->read_allocated); + gs_free_requests(port->port_usb->in, &port->write_pool, + &port->write_allocated); status = -EIO; } @@ -1315,8 +1337,12 @@ void gserial_disconnect(struct gserial *gser) spin_lock_irqsave(&port->port_lock, flags); if (port->open_count == 0 && !port->openclose) gs_buf_free(&port->port_write_buf); - gs_free_requests(gser->out, &port->read_pool); - gs_free_requests(gser->out, &port->read_queue); - gs_free_requests(gser->in, &port->write_pool); + gs_free_requests(gser->out, &port->read_pool, NULL); + gs_free_requests(gser->out, &port->read_queue, NULL); + gs_free_requests(gser->in, &port->write_pool, NULL); + + port->read_allocated = port->read_started = + port->write_allocated = port->write_started = 0; + spin_unlock_irqrestore(&port->port_lock, flags); } |
