On Fri, 4 Mar 2016, yoma sophian wrote: > hi Alan and Peter: > >> > >> Backtrace: > >> [<bf04ebec>] (ehci_handle_start_intr_unlinks [ehci_hcd]) from > >> [<bf04ffb0>] (ehci_bus_suspend+0x388/0x464 [ehci_hcd]) > > > > Since there aren't any devices registered on the USB bus yet, > > ehci_handle_start_intr_unlink() should do nothing. It iterates over > > ehci->intr_unlink, but that list should be empty. > Per Alan's kind reminding, I found my problem comes from improper > initialization of intr_unlink ^^ > > BTW, when I disable BH support in hcd driver. > I get below recursion of spin lock sometimes. > Did I missing anything once disable BH? Yes, you missed a very important fact: ehci-hcd _requires_ BH support! 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
