diff options
| author | Greg Suarez <gpsuarez2512@gmail.com> | 2013-10-29 21:29:10 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-10-30 04:02:41 +0400 |
| commit | 73e06865ead1bec8d1c179e1c647dc77adde9116 (patch) | |
| tree | 01e167bd8665aab09998994b83338f5d790377b0 | |
| parent | 32e24930fb71c47a1366325b6f139e039cacaca4 (diff) | |
| download | linux-73e06865ead1bec8d1c179e1c647dc77adde9116.tar.xz | |
USB: cdc-wdm: support back-to-back USB_CDC_NOTIFY_RESPONSE_AVAILABLE notifications
Some MBIM devices send back-to-back USB_CDC_NOTIFY_RESPONSE_AVAILABLE notifications
when sending a message over multiple fragments or when there are unsolicited
messages available.
Count up the number of USB_CDC_NOTIFY_RESPONSE_AVAILABLE notifications received
and decrement the count and submit the urb for the next response each time userspace
completes a read the response.
Signed-off-by: Greg Suarez <gsuarez@smithmicro.com>
Acked-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/class/cdc-wdm.c | 38 |
1 files changed, 34 insertions, 4 deletions
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index d3318a0df8ee..589ea58d5d66 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -101,6 +101,7 @@ struct wdm_device { struct work_struct rxwork; int werr; int rerr; + int resp_count; struct list_head device_list; int (*manage_power)(struct usb_interface *, int); @@ -262,9 +263,9 @@ static void wdm_int_callback(struct urb *urb) } spin_lock(&desc->iuspin); - clear_bit(WDM_READ, &desc->flags); responding = test_and_set_bit(WDM_RESPONDING, &desc->flags); - if (!responding && !test_bit(WDM_DISCONNECTING, &desc->flags) + if (!desc->resp_count++ && !responding + && !test_bit(WDM_DISCONNECTING, &desc->flags) && !test_bit(WDM_SUSPENDING, &desc->flags)) { rv = usb_submit_urb(desc->response, GFP_ATOMIC); dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d", @@ -521,10 +522,36 @@ retry: desc->length -= cntr; /* in case we had outstanding data */ - if (!desc->length) + if (!desc->length) { clear_bit(WDM_READ, &desc->flags); - spin_unlock_irq(&desc->iuspin); + if (--desc->resp_count) { + set_bit(WDM_RESPONDING, &desc->flags); + spin_unlock_irq(&desc->iuspin); + + rv = usb_submit_urb(desc->response, GFP_KERNEL); + if (rv) { + dev_err(&desc->intf->dev, + "%s: usb_submit_urb failed with result %d\n", + __func__, rv); + spin_lock_irq(&desc->iuspin); + clear_bit(WDM_RESPONDING, &desc->flags); + spin_unlock_irq(&desc->iuspin); + + if (rv == -ENOMEM) { + rv = schedule_work(&desc->rxwork); + if (rv) + dev_err(&desc->intf->dev, "Cannot schedule work\n"); + } else { + spin_lock_irq(&desc->iuspin); + desc->resp_count = 0; + spin_unlock_irq(&desc->iuspin); + } + } + } else + spin_unlock_irq(&desc->iuspin); + } else + spin_unlock_irq(&desc->iuspin); rv = cntr; @@ -635,6 +662,9 @@ static int wdm_release(struct inode *inode, struct file *file) if (!test_bit(WDM_DISCONNECTING, &desc->flags)) { dev_dbg(&desc->intf->dev, "wdm_release: cleanup"); kill_urbs(desc); + spin_lock_irq(&desc->iuspin); + desc->resp_count = 0; + spin_unlock_irq(&desc->iuspin); desc->manage_power(desc->intf, 0); } else { /* must avoid dev_printk here as desc->intf is invalid */ |