From bodonoghue@codehermit.ie Sat Jan 27 04:16:32 2007 From: Bryan O'Donoghue Date: Sat, 27 Jan 2007 12:16:32 +0000 Subject: USB: fix g_serial small error To: Greg KH Cc: linux-usb-devel@lists.sourceforge.net Message-ID: <20070127121632.3738c6f4@localhost.localdomain> A SET_LINE_CODING control request should return a zero length packet as an ACK to the host, during the status phase of a USB transaction. The return value of gs_setup_class() is treated as the number of bytes to write in the status phase of the control request, by gs_setup(). For this case, the value returned by gs_setup_class should be zero for SET_LINE_CODING but, right now, appears to be sizeof(struct usb_cdc_line_coding). However, if after doing the memcpy of the line coding descriptor we set the variable "ret" to be zero, we should return the appropiate ZLP to the host as an ACK in the status phase of the control request. I've tested this out using Linux as both host and slave and confirmed that the following small change fixes the spurious return of sizeof(struct usb_cdc_line_coding)/wLength bytes in the status phase of a USB_CDC_REQ_SET_LINE_CODING request. It's not a huge bug but, it is worth fixing. Signed-off-by: Bryan O'Donoghue Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/serial.c | 1 + 1 file changed, 1 insertion(+) --- gregkh-2.6.orig/drivers/usb/gadget/serial.c +++ gregkh-2.6/drivers/usb/gadget/serial.c @@ -1699,6 +1699,7 @@ static int gs_setup_class(struct usb_gad memcpy(&port->port_line_coding, req->buf, ret); spin_unlock(&port->port_lock); } + ret = 0; break; case USB_CDC_REQ_GET_LINE_CODING: