Messages in this thread Patch in this message | | | Date | Fri, 28 Jan 2005 00:23:00 +0100 | From | Nico Huber <> | Subject | Logitech Cordeless Desktop Keyboard fails to report class descriptor |
| |
The receiver of my Logitech Cordeless Desktop fails to report the keyboard's class descriptor most times I insert the usb-hid module since I changed to linux 2.6. The modell of the receiver is C-BD9-DUAL REV C. The request seems not to fail but the count of received characters is zero.
As I said it only fails most times, I worked around making the following changes in drivers/usb/input/hid-core.c from linux-2.6.11-rc2:
Following the good example of drivers/usb/core/message.c line 575, I initialized the buffer in hid_get_class_descriptor() to zero. In the loop of hid_get_class_descriptor() not waiting for any result but waiting for a result wich is lower the requested size of the class descriptor (line 1290). usb_hid_configure() should not try to parse the expected length but the received (line 1653).
attached is a patch to linux-2.6.11-rc2 with these changes
Nico Huber . --- a/drivers/usb/input/hid-core.c 2005-01-27 23:59:52.000000000 +0100 +++ b/drivers/usb/input/hid-core.c 2005-01-28 00:06:31.000000000 +0100 @@ -1282,12 +1282,15 @@ unsigned char type, void *buf, int size) { int result, retries = 4; + + memset(buf,0,size); // Make sure we parse really received data + do { result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), USB_REQ_GET_DESCRIPTOR, USB_RECIP_INTERFACE | USB_DIR_IN, (type << 8), ifnum, buf, size, HZ * USB_CTRL_GET_TIMEOUT); retries--; - } while (result < 0 && retries); + } while (result < size && retries); return result; } @@ -1650,7 +1653,7 @@ printk("\n"); #endif - if (!(hid = hid_parse_report(rdesc, rsize))) { + if (!(hid = hid_parse_report(rdesc, n))) { dbg("parsing report descriptor failed"); kfree(rdesc); return NULL; | |