net: usb: kaweth: Remove last user of kaweth_control()

kaweth_async_set_rx_mode() invokes kaweth_contol() and has two callers:

- kaweth_open() which is invoked from preemptible context
.
- kaweth_start_xmit() which holds a spinlock and has bottom halfs disabled.

If called from kaweth_start_xmit() kaweth_async_set_rx_mode() obviously
cannot block, which means it can't call kaweth_control(). This is detected
with an in_interrupt() check.

Replace the in_interrupt() check in kaweth_async_set_rx_mode() with an
argument which is set true by the caller if the context is safe to sleep,
otherwise false.

Now kaweth_control() is only called from preemptible context which means
there is no need for GFP_ATOMIC allocations anymore. Replace it with
usb_control_msg(). Cleanup the code a bit while at it.

Finally remove kaweth_control() since the last user is gone.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/usb/kaweth.c b/drivers/net/usb/kaweth.c
index 25eeb15..144c686 100644 (file)
--- a/drivers/net/usb/kaweth.c
+++ b/drivers/net/usb/kaweth.c
@@ -103,10 +103,6 @@ static int kaweth_probe(
                const struct usb_device_id *id  /* from id_table */
        );
 static void kaweth_disconnect(struct usb_interface *intf);
-static int kaweth_internal_control_msg(struct usb_device *usb_dev,
-                                      unsigned int pipe,
-                                      struct usb_ctrlrequest *cmd, void *data,
-                                      int len, int timeout);
 static int kaweth_suspend(struct usb_interface *intf, pm_message_t message);
 static int kaweth_resume(struct usb_interface *intf);
 
@@ -236,48 +232,6 @@ struct kaweth_device
 };
 
 /****************************************************************
- *     kaweth_control
- ****************************************************************/
-static int kaweth_control(struct kaweth_device *kaweth,
-                         unsigned int pipe,
-                         __u8 request,
-                         __u8 requesttype,
-                         __u16 value,
-                         __u16 index,
-                         void *data,
-                         __u16 size,
-                         int timeout)
-{
-       struct usb_ctrlrequest *dr;
-       int retval;
-
-       if(in_interrupt()) {
-               netdev_dbg(kaweth->net, "in_interrupt()\n");
-               return -EBUSY;
-       }
-
-       dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
-       if (!dr)
-               return -ENOMEM;
-
-       dr->bRequestType = requesttype;
-       dr->bRequest = request;
-       dr->wValue = cpu_to_le16(value);
-       dr->wIndex = cpu_to_le16(index);
-       dr->wLength = cpu_to_le16(size);
-
-       retval = kaweth_internal_control_msg(kaweth->dev,
-                                            pipe,
-                                            dr,
-                                            data,
-                                            size,
-                                            timeout);
-
-       kfree(dr);
-       return retval;
-}
-
-/****************************************************************
  *     kaweth_read_configuration
  ****************************************************************/
 static int kaweth_read_configuration(struct kaweth_device *kaweth)
@@ -531,7 +485,8 @@ static int kaweth_resubmit_rx_urb(struct kaweth_device *kaweth,
        return result;
 }
 
-static void kaweth_async_set_rx_mode(struct kaweth_device *kaweth);
+static void kaweth_async_set_rx_mode(struct kaweth_device *kaweth,
+                                    bool may_sleep);
 
 /****************************************************************
  *     kaweth_usb_receive
@@ -661,7 +616,7 @@ static int kaweth_open(struct net_device *net)
 
        netif_start_queue(net);
 
-       kaweth_async_set_rx_mode(kaweth);
+       kaweth_async_set_rx_mode(kaweth, true);
        return 0;
 
 err_out:
@@ -749,7 +704,7 @@ static netdev_tx_t kaweth_start_xmit(struct sk_buff *skb,
 
        spin_lock_irq(&kaweth->device_lock);
 
-       kaweth_async_set_rx_mode(kaweth);
+       kaweth_async_set_rx_mode(kaweth, false);
        netif_stop_queue(net);
        if (IS_BLOCKED(kaweth->status)) {
                goto skip;
@@ -826,36 +781,31 @@ static void kaweth_set_rx_mode(struct net_device *net)
 /****************************************************************
  *     kaweth_async_set_rx_mode
  ****************************************************************/
-static void kaweth_async_set_rx_mode(struct kaweth_device *kaweth)
+static void kaweth_async_set_rx_mode(struct kaweth_device *kaweth,
+                                    bool may_sleep)
 {
-       int result;
+       int ret;
        __u16 packet_filter_bitmap = kaweth->packet_filter_bitmap;
 
        kaweth->packet_filter_bitmap = 0;
        if (packet_filter_bitmap == 0)
                return;
 
-       if (in_interrupt())
+       if (!may_sleep)
                return;
 
-       result = kaweth_control(kaweth,
-                               usb_sndctrlpipe(kaweth->dev, 0),
-                               KAWETH_COMMAND_SET_PACKET_FILTER,
-                               USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE,
-                               packet_filter_bitmap,
-                               0,
-                               (void *)&kaweth->scratch,
-                               0,
-                               KAWETH_CONTROL_TIMEOUT);
-
-       if(result < 0) {
+       ret = usb_control_msg(kaweth->dev, usb_sndctrlpipe(kaweth->dev, 0),
+                             KAWETH_COMMAND_SET_PACKET_FILTER,
+                             USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE,
+                             packet_filter_bitmap, 0,
+                             &kaweth->scratch, 0,
+                             KAWETH_CONTROL_TIMEOUT);
+       if (ret < 0)
                dev_err(&kaweth->intf->dev, "Failed to set Rx mode: %d\n",
-                       result);
-       }
-       else {
+                       ret);
+       else
                netdev_dbg(kaweth->net, "Set Rx mode to %d\n",
                           packet_filter_bitmap);
-       }
 }
 
 /****************************************************************
@@ -1163,88 +1113,4 @@ static void kaweth_disconnect(struct usb_interface *intf)
 }
 
 
-// FIXME this completion stuff is a modified clone of
-// an OLD version of some stuff in usb.c ...
-struct usb_api_data {
-       wait_queue_head_t wqh;
-       int done;
-};
-
-/*-------------------------------------------------------------------*
- * completion handler for compatibility wrappers (sync control/bulk) *
- *-------------------------------------------------------------------*/
-static void usb_api_blocking_completion(struct urb *urb)
-{
-        struct usb_api_data *awd = (struct usb_api_data *)urb->context;
-
-       awd->done=1;
-       wake_up(&awd->wqh);
-}
-
-/*-------------------------------------------------------------------*
- *                         COMPATIBILITY STUFF                       *
- *-------------------------------------------------------------------*/
-
-// Starts urb and waits for completion or timeout
-static int usb_start_wait_urb(struct urb *urb, int timeout, int* actual_length)
-{
-       struct usb_api_data awd;
-        int status;
-
-        init_waitqueue_head(&awd.wqh);
-        awd.done = 0;
-
-        urb->context = &awd;
-        status = usb_submit_urb(urb, GFP_ATOMIC);
-        if (status) {
-                // something went wrong
-                usb_free_urb(urb);
-                return status;
-        }
-
-       if (!wait_event_timeout(awd.wqh, awd.done, timeout)) {
-                // timeout
-                dev_warn(&urb->dev->dev, "usb_control/bulk_msg: timeout\n");
-                usb_kill_urb(urb);  // remove urb safely
-                status = -ETIMEDOUT;
-        }
-       else {
-                status = urb->status;
-       }
-
-        if (actual_length) {
-                *actual_length = urb->actual_length;
-       }
-
-        usb_free_urb(urb);
-        return status;
-}
-
-/*-------------------------------------------------------------------*/
-// returns status (negative) or length (positive)
-static int kaweth_internal_control_msg(struct usb_device *usb_dev,
-                                      unsigned int pipe,
-                                      struct usb_ctrlrequest *cmd, void *data,
-                                      int len, int timeout)
-{
-        struct urb *urb;
-        int retv;
-        int length = 0; /* shut up GCC */
-
-       urb = usb_alloc_urb(0, GFP_ATOMIC);
-        if (!urb)
-                return -ENOMEM;
-
-        usb_fill_control_urb(urb, usb_dev, pipe, (unsigned char*)cmd, data,
-                        len, usb_api_blocking_completion, NULL);
-
-        retv = usb_start_wait_urb(urb, timeout, &length);
-        if (retv < 0) {
-                return retv;
-       }
-        else {
-                return length;
-       }
-}
-
 module_usb_driver(kaweth_driver);