commit fb95c7cf5600b7b74412f27dfb39a1e13fd8a90d
author Chunfeng Yun <chunfeng.yun@mediatek.com> Mon Mar 08 10:52:05 2021 +0800
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> Wed Mar 10 09:37:17 2021 +0100
tree a26adef0d2e1159293afa37941a1970bd206d2a5
parent 14295a150050acfc3a1260ee3d2114b0b824199f

usb: common: add function to get interval expressed in us unit

Add a new function to convert bInterval into the time expressed
in 1us unit.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/25c8a09b055f716c1e5bf11fea72c3418f844482.1615170625.git.chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/endpoint.c

diff --git a/drivers/usb/core/endpoint.c b/drivers/usb/core/endpoint.c
index 903426b..a253081 100644
--- a/drivers/usb/core/endpoint.c
+++ b/drivers/usb/core/endpoint.c
@@ -84,40 +84,13 @@ static ssize_t interval_show(struct device *dev, struct device_attribute *attr,
 			     char *buf)
 {
 	struct ep_device *ep = to_ep_device(dev);
+	unsigned int interval;
 	char unit;
-	unsigned interval = 0;
-	unsigned in;
 
-	in = (ep->desc->bEndpointAddress & USB_DIR_IN);
-
-	switch (usb_endpoint_type(ep->desc)) {
-	case USB_ENDPOINT_XFER_CONTROL:
-		if (ep->udev->speed == USB_SPEED_HIGH)
-			/* uframes per NAK */
-			interval = ep->desc->bInterval;
-		break;
-
-	case USB_ENDPOINT_XFER_ISOC:
-		interval = 1 << (ep->desc->bInterval - 1);
-		break;
-
-	case USB_ENDPOINT_XFER_BULK:
-		if (ep->udev->speed == USB_SPEED_HIGH && !in)
-			/* uframes per NAK */
-			interval = ep->desc->bInterval;
-		break;
-
-	case USB_ENDPOINT_XFER_INT:
-		if (ep->udev->speed == USB_SPEED_HIGH)
-			interval = 1 << (ep->desc->bInterval - 1);
-		else
-			interval = ep->desc->bInterval;
-		break;
-	}
-	interval *= (ep->udev->speed == USB_SPEED_HIGH) ? 125 : 1000;
-	if (interval % 1000)
+	interval = usb_decode_interval(ep->desc, ep->udev->speed);
+	if (interval % 1000) {
 		unit = 'u';
-	else {
+	} else {
 		unit = 'm';
 		interval /= 1000;
 	}