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path: root/drivers/usb/class/cdc-wdm.c
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Diffstat (limited to 'drivers/usb/class/cdc-wdm.c')
-rw-r--r--drivers/usb/class/cdc-wdm.c54
1 files changed, 31 insertions, 23 deletions
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 86ee39db013f..7556c0dac908 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -92,7 +92,6 @@ struct wdm_device {
u16 wMaxCommand;
u16 wMaxPacketSize;
__le16 inum;
- int reslength;
int length;
int read;
int count;
@@ -214,6 +213,11 @@ static void wdm_in_callback(struct urb *urb)
if (desc->rerr == 0 && status != -EPIPE)
desc->rerr = status;
+ if (length == 0) {
+ dev_dbg(&desc->intf->dev, "received ZLP\n");
+ goto skip_zlp;
+ }
+
if (length + desc->length > desc->wMaxCommand) {
/* The buffer would overflow */
set_bit(WDM_OVERFLOW, &desc->flags);
@@ -221,19 +225,20 @@ static void wdm_in_callback(struct urb *urb)
/* we may already be in overflow */
if (!test_bit(WDM_OVERFLOW, &desc->flags)) {
memmove(desc->ubuf + desc->length, desc->inbuf, length);
- desc->length += length;
- desc->reslength = length;
+ smp_wmb(); /* against wdm_read() */
+ WRITE_ONCE(desc->length, desc->length + length);
}
}
skip_error:
if (desc->rerr) {
/*
- * Since there was an error, userspace may decide to not read
- * any data after poll'ing.
+ * If there was a ZLP or an error, userspace may decide to not
+ * read any data after poll'ing.
* We should respond to further attempts from the device to send
* data, so that we can get unstuck.
*/
+skip_zlp:
schedule_work(&desc->service_outs_intr);
} else {
set_bit(WDM_READ, &desc->flags);
@@ -529,6 +534,7 @@ static ssize_t wdm_read
return -ERESTARTSYS;
cntr = READ_ONCE(desc->length);
+ smp_rmb(); /* against wdm_in_callback() */
if (cntr == 0) {
desc->read = 0;
retry:
@@ -585,15 +591,6 @@ retry:
goto retry;
}
- if (!desc->reslength) { /* zero length read */
- dev_dbg(&desc->intf->dev, "zero length - clearing WDM_READ\n");
- clear_bit(WDM_READ, &desc->flags);
- rv = service_outstanding_interrupt(desc);
- spin_unlock_irq(&desc->iuspin);
- if (rv < 0)
- goto err;
- goto retry;
- }
cntr = desc->length;
spin_unlock_irq(&desc->iuspin);
}
@@ -726,7 +723,7 @@ static int wdm_open(struct inode *inode, struct file *file)
rv = -EBUSY;
goto out;
}
-
+ smp_rmb(); /* ordered against wdm_wwan_port_stop() */
rv = usb_autopm_get_interface(desc->intf);
if (rv < 0) {
dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
@@ -829,6 +826,7 @@ static struct usb_class_driver wdm_class = {
static int wdm_wwan_port_start(struct wwan_port *port)
{
struct wdm_device *desc = wwan_port_get_drvdata(port);
+ int rv;
/* The interface is both exposed via the WWAN framework and as a
* legacy usbmisc chardev. If chardev is already open, just fail
@@ -848,7 +846,15 @@ static int wdm_wwan_port_start(struct wwan_port *port)
wwan_port_txon(port);
/* Start getting events */
- return usb_submit_urb(desc->validity, GFP_KERNEL);
+ rv = usb_submit_urb(desc->validity, GFP_KERNEL);
+ if (rv < 0) {
+ wwan_port_txoff(port);
+ desc->manage_power(desc->intf, 0);
+ /* this must be last lest we race with chardev open */
+ clear_bit(WDM_WWAN_IN_USE, &desc->flags);
+ }
+
+ return rv;
}
static void wdm_wwan_port_stop(struct wwan_port *port)
@@ -859,8 +865,10 @@ static void wdm_wwan_port_stop(struct wwan_port *port)
poison_urbs(desc);
desc->manage_power(desc->intf, 0);
clear_bit(WDM_READ, &desc->flags);
- clear_bit(WDM_WWAN_IN_USE, &desc->flags);
unpoison_urbs(desc);
+ smp_wmb(); /* ordered against wdm_open() */
+ /* this must be last lest we open a poisoned device */
+ clear_bit(WDM_WWAN_IN_USE, &desc->flags);
}
static void wdm_wwan_port_tx_complete(struct urb *urb)
@@ -868,7 +876,7 @@ static void wdm_wwan_port_tx_complete(struct urb *urb)
struct sk_buff *skb = urb->context;
struct wdm_device *desc = skb_shinfo(skb)->destructor_arg;
- usb_autopm_put_interface(desc->intf);
+ usb_autopm_put_interface_async(desc->intf);
wwan_port_txon(desc->wwanp);
kfree_skb(skb);
}
@@ -898,7 +906,7 @@ static int wdm_wwan_port_tx(struct wwan_port *port, struct sk_buff *skb)
req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
req->wValue = 0;
- req->wIndex = desc->inum;
+ req->wIndex = desc->inum; /* already converted */
req->wLength = cpu_to_le16(skb->len);
skb_shinfo(skb)->destructor_arg = desc;
@@ -1005,7 +1013,7 @@ static void service_interrupt_work(struct work_struct *work)
spin_lock_irq(&desc->iuspin);
service_outstanding_interrupt(desc);
- if (!desc->resp_count) {
+ if (!desc->resp_count && (desc->length || desc->rerr)) {
set_bit(WDM_READ, &desc->flags);
wake_up(&desc->wait);
}
@@ -1021,7 +1029,7 @@ static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor
int rv = -ENOMEM;
struct wdm_device *desc;
- desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
+ desc = kzalloc_obj(struct wdm_device);
if (!desc)
goto out;
INIT_LIST_HEAD(&desc->device_list);
@@ -1044,10 +1052,10 @@ static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor
desc->wMaxPacketSize = usb_endpoint_maxp(ep);
- desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
+ desc->orq = kmalloc_obj(struct usb_ctrlrequest);
if (!desc->orq)
goto err;
- desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
+ desc->irq = kmalloc_obj(struct usb_ctrlrequest);
if (!desc->irq)
goto err;