[RFC 3/5] hid: Parse the device before adding it

[Henrik Rydberg]

The hid bus is populated by devices created by the usb and bluetooth
subsystems. The hid device is then broadcast to userland via uevents.
Currently, the parsing of the hid reports is done during probe of
the hid device, after the device has been broadcast. In order to
allow for the report descriptors to influence the device properties,
it is desirable to parse the device _before_ it is broadcast to
userland. In actuality, the parsing depends only accidentally on
the driver being present, so it can be trivially achieved.

Something also needs to be done for the report_fixup handler, which
seems to be the only hard device-driver coupling in the code.

Signed-off-by: Henrik Rydberg <rydberg@xxxxxxxxxxx>
---
 drivers/hid/hid-core.c        |    2 +-
 drivers/hid/usbhid/hid-core.c |    5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 35ba9d9..8a7b59e 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -658,7 +658,7 @@ int hid_parse_report(struct hid_device *device, __u8 *start,
 		hid_parser_reserved
 	};
 
-	if (device->driver->report_fixup)
+	if (device->driver && device->driver->report_fixup)
 		start = device->driver->report_fixup(device, start, &size);
 
 	device->rdesc = kmemdup(start, size, GFP_KERNEL);
diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index 5bf91db..e63613b 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -1266,6 +1266,11 @@ static int usbhid_probe(struct usb_interface *intf, const struct usb_device_id *
 	if (usb_string(dev, dev->descriptor.iSerialNumber, hid->uniq, 64) <= 0)
 		hid->uniq[0] = 0;
 
+	ret = hid_parse(hid);
+	if (ret)
+		goto err;
+
+
 	usbhid = kzalloc(sizeof(*usbhid), GFP_KERNEL);
 	if (usbhid == NULL) {
 		ret = -ENOMEM;
-- 
1.7.9.5

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