On Monday 09 April 2007 4:35 pm, Greg KH wrote: > On Mon, Apr 09, 2007 at 11:52:31AM -0400, Alan Stern wrote: > > There is one significant difference between the behavior of root hubs > > (as embodied in host controller hardware) and external hubs: When a > > remote-wakeup signal is received, an external hub sends an interrupt > > message at the _end_ of the resume sequence but a root hub generates > > and interrupt at the _beginning_ of the resume sequence. The host > > system must poll for the end of the sequence. > > > > When ehci-hcd was converted to interrupt-driven operation instead of > > using polling, the remaining need for this particular poll was > > overlooked. This patch (as894) fixes the problem. > > > > Signed-off-by: Alan Stern <[EMAIL PROTECTED]> > > > > --- > > > > Greg: > > > > This needs to go into 2.6.21. You can demonstrate the regression quite > > easily, as follows: Plug in a high-speed device, like a USB flash drive, > > to prevent the root hub from suspending. Then plug in an unpopulated > > high-speed hub. Wait a couple of seconds for the hub to be suspended, > > then try plugging anything into the hub. Without this patch, nothing will > > happen. > > Has anyone reported this happening? I think only user noticed bugs > should go into the tree at this point in time.
Maybe ... there was one regression that was bisected down to Marcelo's "switch to IRQs" patch. It was one of the IPOD things, reported against a 2.6.21-rc4 kernel. Similar "nothing happens" symptom. This patch looks right to me. The reset and resume timers *must* be managed manually; usbcore doesn't provide a replacement (and IMO should not even try). - Dave ------------------------------------------------------------------------- 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
