[PATCH 1/1 v2] HID: don't grab devices with no input

[Jiri Slaby]

Some devices have no input interrupt endpoint. These won't be handled
by usbhid, but currently they are not refused and reside on hid bus.

Perform this checking earlier so that we refuse to control such
a device early enough (and not pass it to the hid bus at all).

Signed-off-by: Jiri Slaby <jirislaby@xxxxxxxxx>
---
 drivers/hid/usbhid/hid-core.c |   17 +++++++++++------
 1 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index 05402e9..9c9bd4c 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -850,12 +850,6 @@ static int usbhid_start(struct hid_device *hid)
 		}
 	}
 
-	if (!usbhid->urbin) {
-		err_hid("couldn't find an input interrupt endpoint");
-		ret = -ENODEV;
-		goto fail;
-	}
-
 	init_waitqueue_head(&usbhid->wait);
 	INIT_WORK(&usbhid->reset_work, hid_reset);
 	setup_timer(&usbhid->io_retry, hid_retry_timeout, (unsigned long) hid);
@@ -958,15 +952,26 @@ static struct hid_ll_driver usb_hid_driver = {
 
 static int hid_probe(struct usb_interface *intf, const struct usb_device_id *id)
 {
+	struct usb_host_interface *interface = intf->cur_altsetting;
 	struct usb_device *dev = interface_to_usbdev(intf);
 	struct usbhid_device *usbhid;
 	struct hid_device *hid;
+	unsigned int n, has_in = 0;
 	size_t len;
 	int ret;
 
 	dbg_hid("HID probe called for ifnum %d\n",
 			intf->altsetting->desc.bInterfaceNumber);
 
+	for (n = 0; n < interface->desc.bNumEndpoints; n++)
+		if (usb_endpoint_is_int_in(&interface->endpoint[n].desc))
+			has_in++;
+	if (!has_in) {
+		dev_err(&intf->dev, "couldn't find an input interrupt "
+				"endpoint");
+		return -ENODEV;
+	}
+
 	hid = hid_allocate_device();
 	if (IS_ERR(hid))
 		return PTR_ERR(hid);
-- 
1.6.0.4

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