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authorOliver Neukum <oliver@neukum.org>2008-06-24 13:56:10 (GMT)
committerGreg Kroah-Hartman <gregkh@suse.de>2008-07-21 22:16:36 (GMT)
commit17d80d562fd78a035e994afde88f354973e76236 (patch)
treef7fb0410119569b88da3f7e228dc700e1ccf357b
parent11ea859d64b69a747d6b060b9ed1520eab1161fe (diff)
downloadlinux-17d80d562fd78a035e994afde88f354973e76236.tar.xz
USB: autosuspend for cdc-wdm
this patch implements - suspend/resume - aggressive autosuspend for the cdc-wdm driver - pre/post_reset Signed-off-by: Oliver Neukum <oneukum@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/usb/class/cdc-wdm.c107
1 files changed, 101 insertions, 6 deletions
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 3a656f8..1103ce70 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -88,6 +88,7 @@ struct wdm_device {
dma_addr_t ihandle;
struct mutex wlock;
struct mutex rlock;
+ struct mutex plock;
wait_queue_head_t wait;
struct work_struct rxwork;
int werr;
@@ -248,6 +249,7 @@ exit:
static void kill_urbs(struct wdm_device *desc)
{
+ /* the order here is essential */
usb_kill_urb(desc->command);
usb_kill_urb(desc->validity);
usb_kill_urb(desc->response);
@@ -300,6 +302,9 @@ static ssize_t wdm_write
if (r)
goto outnl;
+ r = usb_autopm_get_interface(desc->intf);
+ if (r < 0)
+ goto outnp;
r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
&desc->flags));
if (r < 0)
@@ -354,6 +359,8 @@ static ssize_t wdm_write
req->wIndex);
}
out:
+ usb_autopm_put_interface(desc->intf);
+outnp:
mutex_unlock(&desc->wlock);
outnl:
return rv < 0 ? rv : count;
@@ -378,6 +385,11 @@ retry:
rv = wait_event_interruptible(desc->wait,
test_bit(WDM_READ, &desc->flags));
+ if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
+ rv = -ENODEV;
+ goto err;
+ }
+ usb_mark_last_busy(interface_to_usbdev(desc->intf));
if (rv < 0) {
rv = -ERESTARTSYS;
goto err;
@@ -485,18 +497,28 @@ static int wdm_open(struct inode *inode, struct file *file)
if (test_bit(WDM_DISCONNECTING, &desc->flags))
goto out;
- desc->count++;
+ ;
file->private_data = desc;
- rv = usb_submit_urb(desc->validity, GFP_KERNEL);
-
+ rv = usb_autopm_get_interface(desc->intf);
if (rv < 0) {
- desc->count--;
- err("Error submitting int urb - %d", rv);
+ err("Error autopm - %d", rv);
goto out;
}
- rv = 0;
+ intf->needs_remote_wakeup = 1;
+ mutex_lock(&desc->plock);
+ if (!desc->count++) {
+ rv = usb_submit_urb(desc->validity, GFP_KERNEL);
+ if (rv < 0) {
+ desc->count--;
+ err("Error submitting int urb - %d", rv);
+ }
+ } else {
+ rv = 0;
+ }
+ mutex_unlock(&desc->plock);
+ usb_autopm_put_interface(desc->intf);
out:
mutex_unlock(&wdm_mutex);
return rv;
@@ -507,10 +529,15 @@ static int wdm_release(struct inode *inode, struct file *file)
struct wdm_device *desc = file->private_data;
mutex_lock(&wdm_mutex);
+ mutex_lock(&desc->plock);
desc->count--;
+ mutex_unlock(&desc->plock);
+
if (!desc->count) {
dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
kill_urbs(desc);
+ if (!test_bit(WDM_DISCONNECTING, &desc->flags))
+ desc->intf->needs_remote_wakeup = 0;
}
mutex_unlock(&wdm_mutex);
return 0;
@@ -602,6 +629,7 @@ next_desc:
goto out;
mutex_init(&desc->wlock);
mutex_init(&desc->rlock);
+ mutex_init(&desc->plock);
spin_lock_init(&desc->iuspin);
init_waitqueue_head(&desc->wait);
desc->wMaxCommand = maxcom;
@@ -703,6 +731,7 @@ static void wdm_disconnect(struct usb_interface *intf)
spin_lock_irqsave(&desc->iuspin, flags);
set_bit(WDM_DISCONNECTING, &desc->flags);
set_bit(WDM_READ, &desc->flags);
+ /* to terminate pending flushes */
clear_bit(WDM_IN_USE, &desc->flags);
spin_unlock_irqrestore(&desc->iuspin, flags);
cancel_work_sync(&desc->rxwork);
@@ -713,11 +742,77 @@ static void wdm_disconnect(struct usb_interface *intf)
mutex_unlock(&wdm_mutex);
}
+static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
+{
+ struct wdm_device *desc = usb_get_intfdata(intf);
+ int rv = 0;
+
+ dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
+
+ mutex_lock(&desc->plock);
+ if (interface_to_usbdev(desc->intf)->auto_pm && test_bit(WDM_IN_USE, &desc->flags)) {
+ rv = -EBUSY;
+ } else {
+ cancel_work_sync(&desc->rxwork);
+ kill_urbs(desc);
+ }
+ mutex_unlock(&desc->plock);
+
+ return rv;
+}
+
+static int recover_from_urb_loss(struct wdm_device *desc)
+{
+ int rv = 0;
+
+ if (desc->count) {
+ rv = usb_submit_urb(desc->validity, GFP_NOIO);
+ if (rv < 0)
+ err("Error resume submitting int urb - %d", rv);
+ }
+ return rv;
+}
+static int wdm_resume(struct usb_interface *intf)
+{
+ struct wdm_device *desc = usb_get_intfdata(intf);
+ int rv;
+
+ dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
+ mutex_lock(&desc->plock);
+ rv = recover_from_urb_loss(desc);
+ mutex_unlock(&desc->plock);
+ return rv;
+}
+
+static int wdm_pre_reset(struct usb_interface *intf)
+{
+ struct wdm_device *desc = usb_get_intfdata(intf);
+
+ mutex_lock(&desc->plock);
+ return 0;
+}
+
+static int wdm_post_reset(struct usb_interface *intf)
+{
+ struct wdm_device *desc = usb_get_intfdata(intf);
+ int rv;
+
+ rv = recover_from_urb_loss(desc);
+ mutex_unlock(&desc->plock);
+ return 0;
+}
+
static struct usb_driver wdm_driver = {
.name = "cdc_wdm",
.probe = wdm_probe,
.disconnect = wdm_disconnect,
+ .suspend = wdm_suspend,
+ .resume = wdm_resume,
+ .reset_resume = wdm_resume,
+ .pre_reset = wdm_pre_reset,
+ .post_reset = wdm_post_reset,
.id_table = wdm_ids,
+ .supports_autosuspend = 1,
};
/* --- low level module stuff --- */