1 files changed, 56 insertions, 26 deletions

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 34de475f016e..6dac3b802d41 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -38,6 +38,7 @@
 #include <asm/unaligned.h>
 #include <linux/platform_device.h>
 #include <linux/workqueue.h>
+#include <linux/mutex.h>
 
 #include <linux/usb.h>
 
@@ -1275,13 +1276,16 @@ static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
 
 	if (usb_endpoint_xfer_control(&urb->ep->desc)
 	    && !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP)) {
-		if (hcd->self.uses_dma)
+		if (hcd->self.uses_dma) {
 			urb->setup_dma = dma_map_single(
 					hcd->self.controller,
 					urb->setup_packet,
 					sizeof(struct usb_ctrlrequest),
 					DMA_TO_DEVICE);
-		else if (hcd->driver->flags & HCD_LOCAL_MEM)
+			if (dma_mapping_error(hcd->self.controller,
+						urb->setup_dma))
+				return -EAGAIN;
+		} else if (hcd->driver->flags & HCD_LOCAL_MEM)
 			ret = hcd_alloc_coherent(
 					urb->dev->bus, mem_flags,
 					&urb->setup_dma,
@@ -1293,13 +1297,16 @@ static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
 	if (ret == 0 && urb->transfer_buffer_length != 0
 	    && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
-		if (hcd->self.uses_dma)
+		if (hcd->self.uses_dma) {
 			urb->transfer_dma = dma_map_single (
 					hcd->self.controller,
 					urb->transfer_buffer,
 					urb->transfer_buffer_length,
 					dir);
-		else if (hcd->driver->flags & HCD_LOCAL_MEM) {
+			if (dma_mapping_error(hcd->self.controller,
+						urb->transfer_dma))
+				return -EAGAIN;
+		} else if (hcd->driver->flags & HCD_LOCAL_MEM) {
 			ret = hcd_alloc_coherent(
 					urb->dev->bus, mem_flags,
 					&urb->transfer_dma,
@@ -1589,19 +1596,32 @@ rescan:
 	}
 }
 
-/* Check whether a new configuration or alt setting for an interface
- * will exceed the bandwidth for the bus (or the host controller resources).
- * Only pass in a non-NULL config or interface, not both!
- * Passing NULL for both new_config and new_intf means the device will be
- * de-configured by issuing a set configuration 0 command.
+/**
+ * Check whether a new bandwidth setting exceeds the bus bandwidth.
+ * @new_config: new configuration to install
+ * @cur_alt: the current alternate interface setting
+ * @new_alt: alternate interface setting that is being installed
+ *
+ * To change configurations, pass in the new configuration in new_config,
+ * and pass NULL for cur_alt and new_alt.
+ *
+ * To reset a device's configuration (put the device in the ADDRESSED state),
+ * pass in NULL for new_config, cur_alt, and new_alt.
+ *
+ * To change alternate interface settings, pass in NULL for new_config,
+ * pass in the current alternate interface setting in cur_alt,
+ * and pass in the new alternate interface setting in new_alt.
+ *
+ * Returns an error if the requested bandwidth change exceeds the
+ * bus bandwidth or host controller internal resources.
  */
-int usb_hcd_check_bandwidth(struct usb_device *udev,
+int usb_hcd_alloc_bandwidth(struct usb_device *udev,
 		struct usb_host_config *new_config,
-		struct usb_interface *new_intf)
+		struct usb_host_interface *cur_alt,
+		struct usb_host_interface *new_alt)
 {
 	int num_intfs, i, j;
-	struct usb_interface_cache *intf_cache;
-	struct usb_host_interface *alt = 0;
+	struct usb_host_interface *alt = NULL;
 	int ret = 0;
 	struct usb_hcd *hcd;
 	struct usb_host_endpoint *ep;
@@ -1611,7 +1631,7 @@ int usb_hcd_check_bandwidth(struct usb_device *udev,
 		return 0;
 
 	/* Configuration is being removed - set configuration 0 */
-	if (!new_config && !new_intf) {
+	if (!new_config && !cur_alt) {
 		for (i = 1; i < 16; ++i) {
 			ep = udev->ep_out[i];
 			if (ep)
@@ -1648,19 +1668,12 @@ int usb_hcd_check_bandwidth(struct usb_device *udev,
 			}
 		}
 		for (i = 0; i < num_intfs; ++i) {
+			/* Set up endpoints for alternate interface setting 0 */
+			alt = usb_find_alt_setting(new_config, i, 0);
+			if (!alt)
+				/* No alt setting 0? Pick the first setting. */
+				alt = &new_config->intf_cache[i]->altsetting[0];
 
-			/* Dig the endpoints for alt setting 0 out of the
-			 * interface cache for this interface
-			 */
-			intf_cache = new_config->intf_cache[i];
-			for (j = 0; j < intf_cache->num_altsetting; j++) {
-				if (intf_cache->altsetting[j].desc.bAlternateSetting == 0)
-					alt = &intf_cache->altsetting[j];
-			}
-			if (!alt) {
-				printk(KERN_DEBUG "Did not find alt setting 0 for intf %d\n", i);
-				continue;
-			}
 			for (j = 0; j < alt->desc.bNumEndpoints; j++) {
 				ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]);
 				if (ret < 0)
@@ -1668,6 +1681,22 @@ int usb_hcd_check_bandwidth(struct usb_device *udev,
 			}
 		}
 	}
+	if (cur_alt && new_alt) {
+		/* Drop all the endpoints in the current alt setting */
+		for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) {
+			ret = hcd->driver->drop_endpoint(hcd, udev,
+					&cur_alt->endpoint[i]);
+			if (ret < 0)
+				goto reset;
+		}
+		/* Add all the endpoints in the new alt setting */
+		for (i = 0; i < new_alt->desc.bNumEndpoints; i++) {
+			ret = hcd->driver->add_endpoint(hcd, udev,
+					&new_alt->endpoint[i]);
+			if (ret < 0)
+				goto reset;
+		}
+	}
 	ret = hcd->driver->check_bandwidth(hcd, udev);
 reset:
 	if (ret < 0)
@@ -1984,6 +2013,7 @@ struct usb_hcd *usb_create_hcd (const struct hc_driver *driver,
 #ifdef CONFIG_PM
 	INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
 #endif
+	mutex_init(&hcd->bandwidth_mutex);
 
 	hcd->driver = driver;
 	hcd->product_desc = (driver->product_desc) ? driver->product_desc :