sound: 6fire: move to use usb_control_msg_send() and usb_control_msg_recv()

The usb_control_msg_send() and usb_control_msg_recv() calls can return
an error if a "short" write/read happens, so move the driver over to
using those calls instead, saving some logic in the wrapper functions
that were being used in this driver.

This also resolves a long-staging bug where data on the stack was being
sent in a USB control message, which was not allowed.

Cc: Jaroslav Kysela <perex@perex.cz>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20200914153756.3412156-8-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

sound/usb/6fire/firmware.c

@@ -158,29 +158,17 @@ static int usb6fire_fw_ihex_init(const struct firmware *fw,
 static int usb6fire_fw_ezusb_write(struct usb_device *device,
 		int type, int value, char *data, int len)
 {
-	int ret;
-
-	ret = usb_control_msg(device, usb_sndctrlpipe(device, 0), type,
-			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
-			value, 0, data, len, HZ);
-	if (ret < 0)
-		return ret;
-	else if (ret != len)
-		return -EIO;
-	return 0;
+	return usb_control_msg_send(device, 0, type,
+				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+				    value, 0, data, len, HZ);
 }
 
 static int usb6fire_fw_ezusb_read(struct usb_device *device,
 		int type, int value, char *data, int len)
 {
-	int ret = usb_control_msg(device, usb_rcvctrlpipe(device, 0), type,
-			USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE, value,
-			0, data, len, HZ);
-	if (ret < 0)
-		return ret;
-	else if (ret != len)
-		return -EIO;
-	return 0;
+	return usb_control_msg_recv(device, 0, type,
+				    USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+				    value, 0, data, len, HZ);
 }
 
 static int usb6fire_fw_fpga_write(struct usb_device *device,
@@ -230,7 +218,7 @@ static int usb6fire_fw_ezusb_upload(
 	/* upload firmware image */
 	data = 0x01; /* stop ezusb cpu */
 	ret = usb6fire_fw_ezusb_write(device, 0xa0, 0xe600, &data, 1);
-	if (ret < 0) {
+	if (ret) {
 		kfree(rec);
 		release_firmware(fw);
 		dev_err(&intf->dev,
@@ -242,7 +230,7 @@ static int usb6fire_fw_ezusb_upload(
 	while (usb6fire_fw_ihex_next_record(rec)) { /* write firmware */
 		ret = usb6fire_fw_ezusb_write(device, 0xa0, rec->address,
 				rec->data, rec->len);
-		if (ret < 0) {
+		if (ret) {
 			kfree(rec);
 			release_firmware(fw);
 			dev_err(&intf->dev,
@@ -257,7 +245,7 @@ static int usb6fire_fw_ezusb_upload(
 	if (postdata) { /* write data after firmware has been uploaded */
 		ret = usb6fire_fw_ezusb_write(device, 0xa0, postaddr,
 				postdata, postlen);
-		if (ret < 0) {
+		if (ret) {
 			dev_err(&intf->dev,
 				"unable to upload ezusb firmware %s: post urb.\n",
 				fwname);
@@ -267,7 +255,7 @@ static int usb6fire_fw_ezusb_upload(
 
 	data = 0x00; /* resume ezusb cpu */
 	ret = usb6fire_fw_ezusb_write(device, 0xa0, 0xe600, &data, 1);
-	if (ret < 0) {
+	if (ret) {
 		dev_err(&intf->dev,
 			"unable to upload ezusb firmware %s: end message.\n",
 			fwname);
@@ -302,7 +290,7 @@ static int usb6fire_fw_fpga_upload(
 	end = fw->data + fw->size;
 
 	ret = usb6fire_fw_ezusb_write(device, 8, 0, NULL, 0);
-	if (ret < 0) {
+	if (ret) {
 		kfree(buffer);
 		release_firmware(fw);
 		dev_err(&intf->dev,
@@ -327,7 +315,7 @@ static int usb6fire_fw_fpga_upload(
 	kfree(buffer);
 
 	ret = usb6fire_fw_ezusb_write(device, 9, 0, NULL, 0);
-	if (ret < 0) {
+	if (ret) {
 		dev_err(&intf->dev,
 			"unable to upload fpga firmware: end urb.\n");
 		return ret;
@@ -363,7 +351,7 @@ int usb6fire_fw_init(struct usb_interface *intf)
 	u8 buffer[12];
 
 	ret = usb6fire_fw_ezusb_read(device, 1, 0, buffer, 8);
-	if (ret < 0) {
+	if (ret) {
 		dev_err(&intf->dev,
 			"unable to receive device firmware state.\n");
 		return ret;