From 17d80d562fd78a035e994afde88f354973e76236 Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Tue, 24 Jun 2008 15:56:10 +0200 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/class/cdc-wdm.c | 107 ++++++++++++++++++++++++++++++++++-- 1 file changed, 101 insertions(+), 6 deletions(-) diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index 3a656f8f99..1103ce7016 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 --- */ -- 2.39.5