linux-kernel - [PATCH 22/26] usb: gadget: f_uvc: eliminate abuse of ep->driver data

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Date:	Tue, 15 Sep 2015 16:27:05 +0200
From:	Robert Baldyga <r.baldyga@...sung.com>
To:	balbi@...com
Cc:	gregkh@...uxfoundation.org, linux-usb@...r.kernel.org,
	linux-kernel@...r.kernel.org, b.zolnierkie@...sung.com,
	m.szyprowski@...sung.com, andrzej.p@...sung.com,
	Robert Baldyga <r.baldyga@...sung.com>
Subject: [PATCH 22/26] usb: gadget: f_uvc: eliminate abuse of ep->driver data

Since ep->driver_data is not used for endpoint claiming, neither for
enabled/disabled state storing, we can reduce number of places where
we read or modify it's value, as now it has no particular meaning for
function or framework logic.

In case of f_uvc, ep->driver_data was used only for endpoint claiming
and marking endpoints as enabled, so we can simplify code by reducing
it.

Signed-off-by: Robert Baldyga <r.baldyga@...sung.com>
---
 drivers/usb/gadget/function/f_uvc.c | 42 +++++++------------------------------
 1 file changed, 8 insertions(+), 34 deletions(-)

diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
index 743be34..29b41b5 100644
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c
@@ -280,7 +280,7 @@ uvc_function_get_alt(struct usb_function *f, unsigned interface)
 	else if (interface != uvc->streaming_intf)
 		return -EINVAL;
 	else
-		return uvc->video.ep->driver_data ? 1 : 0;
+		return uvc->video.ep->enabled ? 1 : 0;
 }
 
 static int
@@ -298,18 +298,14 @@ uvc_function_set_alt(struct usb_function *f, unsigned interface, unsigned alt)
 		if (alt)
 			return -EINVAL;
 
-		if (uvc->control_ep->driver_data) {
-			INFO(cdev, "reset UVC Control\n");
-			usb_ep_disable(uvc->control_ep);
-			uvc->control_ep->driver_data = NULL;
-		}
+		INFO(cdev, "reset UVC Control\n");
+		usb_ep_disable(uvc->control_ep);
 
 		if (!uvc->control_ep->desc)
 			if (config_ep_by_speed(cdev->gadget, f, uvc->control_ep))
 				return -EINVAL;
 
 		usb_ep_enable(uvc->control_ep);
-		uvc->control_ep->driver_data = uvc;
 
 		if (uvc->state == UVC_STATE_DISCONNECTED) {
 			memset(&v4l2_event, 0, sizeof(v4l2_event));
@@ -336,10 +332,8 @@ uvc_function_set_alt(struct usb_function *f, unsigned interface, unsigned alt)
 		if (uvc->state != UVC_STATE_STREAMING)
 			return 0;
 
-		if (uvc->video.ep) {
+		if (uvc->video.ep)
 			usb_ep_disable(uvc->video.ep);
-			uvc->video.ep->driver_data = NULL;
-		}
 
 		memset(&v4l2_event, 0, sizeof(v4l2_event));
 		v4l2_event.type = UVC_EVENT_STREAMOFF;
@@ -355,18 +349,14 @@ uvc_function_set_alt(struct usb_function *f, unsigned interface, unsigned alt)
 		if (!uvc->video.ep)
 			return -EINVAL;
 
-		if (uvc->video.ep->driver_data) {
-			INFO(cdev, "reset UVC\n");
-			usb_ep_disable(uvc->video.ep);
-			uvc->video.ep->driver_data = NULL;
-		}
+		INFO(cdev, "reset UVC\n");
+		usb_ep_disable(uvc->video.ep);
 
 		ret = config_ep_by_speed(f->config->cdev->gadget,
 				&(uvc->func), uvc->video.ep);
 		if (ret)
 			return ret;
 		usb_ep_enable(uvc->video.ep);
-		uvc->video.ep->driver_data = uvc;
 
 		memset(&v4l2_event, 0, sizeof(v4l2_event));
 		v4l2_event.type = UVC_EVENT_STREAMON;
@@ -392,15 +382,8 @@ uvc_function_disable(struct usb_function *f)
 
 	uvc->state = UVC_STATE_DISCONNECTED;
 
-	if (uvc->video.ep->driver_data) {
-		usb_ep_disable(uvc->video.ep);
-		uvc->video.ep->driver_data = NULL;
-	}
-
-	if (uvc->control_ep->driver_data) {
-		usb_ep_disable(uvc->control_ep);
-		uvc->control_ep->driver_data = NULL;
-	}
+	usb_ep_disable(uvc->video.ep);
+	usb_ep_disable(uvc->control_ep);
 }
 
 /* --------------------------------------------------------------------------
@@ -651,7 +634,6 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
 		goto error;
 	}
 	uvc->control_ep = ep;
-	ep->driver_data = uvc;
 
 	if (gadget_is_superspeed(c->cdev->gadget))
 		ep = usb_ep_autoconfig_ss(cdev->gadget, &uvc_ss_streaming_ep,
@@ -666,7 +648,6 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
 		goto error;
 	}
 	uvc->video.ep = ep;
-	ep->driver_data = uvc;
 
 	uvc_fs_streaming_ep.bEndpointAddress = uvc->video.ep->address;
 	uvc_hs_streaming_ep.bEndpointAddress = uvc->video.ep->address;
@@ -755,11 +736,6 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
 error:
 	v4l2_device_unregister(&uvc->v4l2_dev);
 
-	if (uvc->control_ep)
-		uvc->control_ep->driver_data = NULL;
-	if (uvc->video.ep)
-		uvc->video.ep->driver_data = NULL;
-
 	if (uvc->control_req)
 		usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
 	kfree(uvc->control_buf);
@@ -886,8 +862,6 @@ static void uvc_unbind(struct usb_configuration *c, struct usb_function *f)
 
 	video_unregister_device(&uvc->vdev);
 	v4l2_device_unregister(&uvc->v4l2_dev);
-	uvc->control_ep->driver_data = NULL;
-	uvc->video.ep->driver_data = NULL;
 
 	usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
 	kfree(uvc->control_buf);
-- 
1.9.1

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