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path: root/drivers/usb/class/cdc-acm.c
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Diffstat (limited to 'drivers/usb/class/cdc-acm.c')
-rw-r--r--drivers/usb/class/cdc-acm.c86
1 files changed, 46 insertions, 40 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 0725b1871f23..efc4373ededb 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -51,6 +51,7 @@
*/
#undef DEBUG
+#undef VERBOSE_DEBUG
#include <linux/kernel.h>
#include <linux/errno.h>
@@ -70,6 +71,9 @@
#include "cdc-acm.h"
+
+#define ACM_CLOSE_TIMEOUT 15 /* seconds to let writes drain */
+
/*
* Version Information
*/
@@ -85,6 +89,12 @@ static DEFINE_MUTEX(open_mutex);
#define ACM_READY(acm) (acm && acm->dev && acm->used)
+#ifdef VERBOSE_DEBUG
+#define verbose 1
+#else
+#define verbose 0
+#endif
+
/*
* Functions for ACM control messages.
*/
@@ -136,19 +146,17 @@ static int acm_wb_alloc(struct acm *acm)
static int acm_wb_is_avail(struct acm *acm)
{
int i, n;
+ unsigned long flags;
n = ACM_NW;
+ spin_lock_irqsave(&acm->write_lock, flags);
for (i = 0; i < ACM_NW; i++) {
n -= acm->wb[i].use;
}
+ spin_unlock_irqrestore(&acm->write_lock, flags);
return n;
}
-static inline int acm_wb_is_used(struct acm *acm, int wbn)
-{
- return acm->wb[wbn].use;
-}
-
/*
* Finish write.
*/
@@ -157,7 +165,6 @@ 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);
@@ -190,40 +197,25 @@ static int acm_start_wb(struct acm *acm, struct acm_wb *wb)
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) {
- spin_unlock_irqrestore(&acm->write_lock, flags);
- 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;
- }
-
rc = acm_start_wb(acm, wb);
spin_unlock_irqrestore(&acm->write_lock, flags);
@@ -488,22 +480,28 @@ urbs:
/* data interface wrote those outgoing bytes */
static void acm_write_bulk(struct urb *urb)
{
- struct acm *acm;
struct acm_wb *wb = urb->context;
+ struct acm *acm = wb->instance;
- dbg("Entering acm_write_bulk with status %d", urb->status);
+ if (verbose || urb->status
+ || (urb->actual_length != urb->transfer_buffer_length))
+ dev_dbg(&acm->data->dev, "tx %d/%d bytes -- > %d\n",
+ urb->actual_length,
+ urb->transfer_buffer_length,
+ urb->status);
- acm = wb->instance;
acm_write_done(acm, wb);
if (ACM_READY(acm))
schedule_work(&acm->work);
+ else
+ wake_up_interruptible(&acm->drain_wait);
}
static void acm_softint(struct work_struct *work)
{
struct acm *acm = container_of(work, struct acm, work);
- dbg("Entering acm_softint.");
-
+
+ dev_vdbg(&acm->data->dev, "tx work\n");
if (!ACM_READY(acm))
return;
tty_wakeup(acm->tty);
@@ -512,7 +510,6 @@ static void acm_softint(struct work_struct *work)
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);
@@ -524,9 +521,6 @@ static void acm_waker(struct work_struct *waker)
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);
}
@@ -628,6 +622,8 @@ static void acm_tty_unregister(struct acm *acm)
kfree(acm);
}
+static int acm_tty_chars_in_buffer(struct tty_struct *tty);
+
static void acm_tty_close(struct tty_struct *tty, struct file *filp)
{
struct acm *acm = tty->driver_data;
@@ -642,6 +638,13 @@ static void acm_tty_close(struct tty_struct *tty, struct file *filp)
if (acm->dev) {
usb_autopm_get_interface(acm->control);
acm_set_control(acm, acm->ctrlout = 0);
+
+ /* try letting the last writes drain naturally */
+ wait_event_interruptible_timeout(acm->drain_wait,
+ (ACM_NW == acm_wb_is_avail(acm))
+ || !acm->dev,
+ ACM_CLOSE_TIMEOUT * HZ);
+
usb_kill_urb(acm->ctrlurb);
for (i = 0; i < ACM_NW; i++)
usb_kill_urb(acm->wb[i].urb);
@@ -697,7 +700,7 @@ 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)
@@ -1072,11 +1075,11 @@ skip_normal_probe:
acm->urb_task.data = (unsigned long) acm;
INIT_WORK(&acm->work, acm_softint);
INIT_WORK(&acm->waker, acm_waker);
+ init_waitqueue_head(&acm->drain_wait);
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);
@@ -1108,9 +1111,11 @@ 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;
}
@@ -1172,6 +1177,7 @@ 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);
@@ -1221,11 +1227,11 @@ static void acm_disconnect(struct usb_interface *intf)
struct acm *acm = usb_get_intfdata(intf);
struct usb_device *usb_dev = interface_to_usbdev(intf);
- mutex_lock(&open_mutex);
- if (!acm || !acm->dev) {
- mutex_unlock(&open_mutex);
+ /* sibling interface is already cleaning up */
+ if (!acm)
return;
- }
+
+ mutex_lock(&open_mutex);
if (acm->country_codes){
device_remove_file(&acm->control->dev,
&dev_attr_wCountryCodes);