"Lu, Yinghai" <[EMAIL PROTECTED]> writes: > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > [EMAIL PROTECTED] > Sent: Tuesday, December 05, 2006 3:01 AM > >>+static int ehci_wait_for_port(int port) >>+{ >>+ unsigned status; >>+ int ret, reps; >>+ for (reps = 0; reps >= 0; reps++) { >>+ status = readl(&ehci_regs->status); >>+ if (status & STS_PCD) { >>+ ret = ehci_reset_port(port); >>+ if (ret == 0) >>+ return 0; >>+ } >>+ } >>+ return -ENOTCONN; >>+} >>+ > > What do you mean by > + for (reps = 0; reps >= 0; reps++) { > ?
If you will not reps is negative. Roughly it is a loop that will timeout eventually if a usb debug cable is not present. Putting some deliberate delays in there so I could be certain of timing out after a second or two would probably be better, but I don't have anything that resembles a good timer at that point. The problem is you have to wait until the ehci notices your usb debug cable before you reset it and get it going and that can be a non-trivial amount of time. So the loop is 100% necessary. So since I didn't know how many loop iterations made sense I allowed it to loop for 2^31 times or until reps goes negative. Eric ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
