USB: simplify the interface of usb_get_status()

This patch simplifies the interface presented by usb_get_status(). Instead of forcing callers to check for the proper data length and convert the status value to host byte order, the function will now do these things itself. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: simplify the interface of usb_get_status()
This patch simplifies the interface presented by usb_get_status(). Instead of forcing callers to check for the proper data length and convert the status value to host byte order, the function will now do these things itself. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Alan Stern · Greg Kroah-Hartman
1 parent b977a3068a
Showing 3 changed files with 15 additions and 17 deletions Side-by-side Diff
drivers/usb/core/hub.c
drivers/usb/core/message.c
drivers/usb/misc/usbtest.c
@@ -1464,11 +1464,10 @@
 	 * and battery-powered root hubs (may provide just 8 mA).
 	 */
 	ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
-	if (ret < 2) {
+	if (ret) {
 		message = "can't get hub status";
 		goto fail;
 	}
-	le16_to_cpus(&hubstatus);
 	hcd = bus_to_hcd(hdev->bus);
 	if (hdev == hdev->bus->root_hub) {
 		if (hcd->power_budget > 0)
@@ -3101,8 +3100,6 @@
 	if (status == 0) {
 		devstatus = 0;
 		status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
-		if (status >= 0)
-			status = (status > 0 ? 0 : -ENODEV);
  
 		/* If a normal resume failed, try doing a reset-resume */
 		if (status && !udev->reset_resume && udev->persist_enabled) {
@@ -3123,7 +3120,6 @@
 	 */
 	} else if (udev->actconfig && !udev->reset_resume) {
 		if (!hub_is_superspeed(udev->parent)) {
-			le16_to_cpus(&devstatus);
 			if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP))
 				status = usb_control_msg(udev,
 						usb_sndctrlpipe(udev, 0),
@@ -3135,7 +3131,6 @@
 		} else {
 			status = usb_get_status(udev, USB_RECIP_INTERFACE, 0,
 					&devstatus);
-			le16_to_cpus(&devstatus);
 			if (!status && devstatus & (USB_INTRF_STAT_FUNC_RW_CAP
 					| USB_INTRF_STAT_FUNC_RW))
 				status =
  
@@ -4481,11 +4476,10 @@
  
 			status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
 					&devstat);
-			if (status < 2) {
+			if (status) {
 				dev_dbg(&udev->dev, "get status %d ?\n", status);
 				goto loop_disable;
 			}
-			le16_to_cpus(&devstat);
 			if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
 				dev_err(&udev->dev,
 					"can't connect bus-powered hub "
@@ -934,13 +934,13 @@
  *
  * This call is synchronous, and may not be used in an interrupt context.
  *
- * Returns the number of bytes received on success, or else the status code
- * returned by the underlying usb_control_msg() call.
+ * Returns 0 and the status value in *@data (in host byte order) on success,
+ * or else the status code from the underlying usb_control_msg() call.
  */
 int usb_get_status(struct usb_device *dev, int type, int target, void *data)
 {
 	int ret;
-	u16 *status = kmalloc(sizeof(*status), GFP_KERNEL);
+	__le16 *status = kmalloc(sizeof(*status), GFP_KERNEL);
  
 	if (!status)
 		return -ENOMEM;
@@ -949,7 +949,12 @@
 		USB_REQ_GET_STATUS, USB_DIR_IN | type, 0, target, status,
 		sizeof(*status), USB_CTRL_GET_TIMEOUT);
  
-	*(u16 *)data = *status;
+	if (ret == 2) {
+		*(u16 *) data = le16_to_cpu(*status);
+		ret = 0;
+	} else if (ret >= 0) {
+		ret = -EIO;
+	}
 	kfree(status);
 	return ret;
 }
@@ -747,9 +747,9 @@
  
 	/* [9.4.5] get_status always works */
 	retval = usb_get_status(udev, USB_RECIP_DEVICE, 0, dev->buf);
-	if (retval != 2) {
+	if (retval) {
 		dev_err(&iface->dev, "get dev status --> %d\n", retval);
-		return (retval < 0) ? retval : -EDOM;
+		return retval;
 	}
  
 	/* FIXME configuration.bmAttributes says if we could try to set/clear
  
@@ -758,9 +758,9 @@
  
 	retval = usb_get_status(udev, USB_RECIP_INTERFACE,
 			iface->altsetting[0].desc.bInterfaceNumber, dev->buf);
-	if (retval != 2) {
+	if (retval) {
 		dev_err(&iface->dev, "get interface status --> %d\n", retval);
-		return (retval < 0) ? retval : -EDOM;
+		return retval;
 	}
 	/* FIXME get status for each endpoint in the interface */
  
@@ -1351,7 +1351,6 @@
 				ep, retval);
 		return retval;
 	}
-	le16_to_cpus(&status);
 	if (status != 1) {
 		ERROR(tdev, "ep %02x bogus status: %04x != 1\n", ep, status);
 		return -EINVAL;
...	...	@@ -1464,11 +1464,10 @@
1464	1464	* and battery-powered root hubs (may provide just 8 mA).
1465	1465	*/
1466	1466	ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
1467		- if (ret < 2) {
	1467	+ if (ret) {
1468	1468	message = "can't get hub status";
1469	1469	goto fail;
1470	1470	}
1471		- le16_to_cpus(&hubstatus);
1472	1471	hcd = bus_to_hcd(hdev->bus);
1473	1472	if (hdev == hdev->bus->root_hub) {
1474	1473	if (hcd->power_budget > 0)
...	...	@@ -3101,8 +3100,6 @@
3101	3100	if (status == 0) {
3102	3101	devstatus = 0;
3103	3102	status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
3104		- if (status >= 0)
3105		- status = (status > 0 ? 0 : -ENODEV);
3106	3103
3107	3104	/* If a normal resume failed, try doing a reset-resume */
3108	3105	if (status && !udev->reset_resume && udev->persist_enabled) {
...	...	@@ -3123,7 +3120,6 @@
3123	3120	*/
3124	3121	} else if (udev->actconfig && !udev->reset_resume) {
3125	3122	if (!hub_is_superspeed(udev->parent)) {
3126		- le16_to_cpus(&devstatus);
3127	3123	if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP))
3128	3124	status = usb_control_msg(udev,
3129	3125	usb_sndctrlpipe(udev, 0),
...	...	@@ -3135,7 +3131,6 @@
3135	3131	} else {
3136	3132	status = usb_get_status(udev, USB_RECIP_INTERFACE, 0,
3137	3133	&devstatus);
3138		- le16_to_cpus(&devstatus);
3139	3134	if (!status && devstatus & (USB_INTRF_STAT_FUNC_RW_CAP
3140	3135	\| USB_INTRF_STAT_FUNC_RW))
3141	3136	status =
3142	3137
...	...	@@ -4481,11 +4476,10 @@
4481	4476
4482	4477	status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
4483	4478	&devstat);
4484		- if (status < 2) {
	4479	+ if (status) {
4485	4480	dev_dbg(&udev->dev, "get status %d ?\n", status);
4486	4481	goto loop_disable;
4487	4482	}
4488		- le16_to_cpus(&devstat);
4489	4483	if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
4490	4484	dev_err(&udev->dev,
4491	4485	"can't connect bus-powered hub "
...	...	@@ -934,13 +934,13 @@
934	934	*
935	935	* This call is synchronous, and may not be used in an interrupt context.
936	936	*
937		- * Returns the number of bytes received on success, or else the status code
938		- * returned by the underlying usb_control_msg() call.
	937	+ * Returns 0 and the status value in *@data (in host byte order) on success,
	938	+ * or else the status code from the underlying usb_control_msg() call.
939	939	*/
940	940	int usb_get_status(struct usb_device dev, int type, int target, void data)
941	941	{
942	942	int ret;
943		- u16 status = kmalloc(sizeof(status), GFP_KERNEL);
	943	+ __le16 status = kmalloc(sizeof(status), GFP_KERNEL);
944	944
945	945	if (!status)
946	946	return -ENOMEM;
...	...	@@ -949,7 +949,12 @@
949	949	USB_REQ_GET_STATUS, USB_DIR_IN \| type, 0, target, status,
950	950	sizeof(*status), USB_CTRL_GET_TIMEOUT);
951	951
952		- (u16 )data = *status;
	952	+ if (ret == 2) {
	953	+ (u16 ) data = le16_to_cpu(*status);
	954	+ ret = 0;
	955	+ } else if (ret >= 0) {
	956	+ ret = -EIO;
	957	+ }
953	958	kfree(status);
954	959	return ret;
955	960	}
...	...	@@ -747,9 +747,9 @@
747	747
748	748	/* [9.4.5] get_status always works */
749	749	retval = usb_get_status(udev, USB_RECIP_DEVICE, 0, dev->buf);
750		- if (retval != 2) {
	750	+ if (retval) {
751	751	dev_err(&iface->dev, "get dev status --> %d\n", retval);
752		- return (retval < 0) ? retval : -EDOM;
	752	+ return retval;
753	753	}
754	754
755	755	/* FIXME configuration.bmAttributes says if we could try to set/clear
756	756
...	...	@@ -758,9 +758,9 @@
758	758
759	759	retval = usb_get_status(udev, USB_RECIP_INTERFACE,
760	760	iface->altsetting[0].desc.bInterfaceNumber, dev->buf);
761		- if (retval != 2) {
	761	+ if (retval) {
762	762	dev_err(&iface->dev, "get interface status --> %d\n", retval);
763		- return (retval < 0) ? retval : -EDOM;
	763	+ return retval;
764	764	}
765	765	/* FIXME get status for each endpoint in the interface */
766	766
...	...	@@ -1351,7 +1351,6 @@
1351	1351	ep, retval);
1352	1352	return retval;
1353	1353	}
1354		- le16_to_cpus(&status);
1355	1354	if (status != 1) {
1356	1355	ERROR(tdev, "ep %02x bogus status: %04x != 1\n", ep, status);
1357	1356	return -EINVAL;