Alan, Thanks, Alan. Using your patch can work around this issue and the most important thing is that the SO bit is not set again. Based on your patch, I'll forward this to customer for tests. Thanks, Frank -----Original Message----- From: Alan Stern [mailto:stern@xxxxxxxxxxxxxxxxxxx] Sent: Wednesday, December 30, 2009 11:06 PM To: Huang, FrankR Cc: USB list Subject: RE: A question about ohci_irq() On Wed, 30 Dec 2009, Huang, FrankR wrote: > Alan, > > Although this method can solve the usb mouse hang, but I found Which method are you talking about? Your patch or my patch? > that from the debug log, the SO bit(SchedulingOverrun) in > HcInterruptStatus register is always set after a period of time. Is it > matter? Or any modification to avoid this? SO should not be set. > I noticed that in kernel code, there is no code to handle the > SchedulingOverrun interrupt. That's because nothing can be done. > In the OHCI spec, it suggests me to lower > the bandwidth. Do I need add some code to this? No. The driver already works correctly. The problem is that you have bad hardware. You need to figure out what's wrong with the hardware and how to work around the bugs. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html