On Sun, 13 Apr 2014, vichy wrote: > hi all: > When I grep "HCD_FLAG_POLL_RH", > I ave some questions: > 1. why this flag only seems used by xhci, uhci, ohci except ehci?
ehci-hcd doesn't need to use the flag, because it has well behaved interrupts. The other drivers do need to use it. > 2. it seems to setup when pcd happen and need to poll port status. > And clear it when hcd_died, hcd_remove, hcd_suspend and no port change > in hub_status_data That's not a question. > 3. if we once set this flag up, we may need to test it when we needed. > But why there is no test bit case in usb driver? There is a test case in drivers/usb/core/hcd.c, but you missed it. > appreciate your kind help in advance, > > PS:Below is my grep results: > # grep -rwn 'HCD_FLAG_POLL_RH' drivers/usb/* You also need to grep in include/linux/usb. See the definition of HCD_POLL_RH. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
