Hi: 2009/10/9 vichy <vichy.kuo@xxxxxxxxx>: > Hi Alan: > > 2009/10/8 Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>: >> On Thu, 8 Oct 2009, vichy wrote: >> >>> Dear all: >>> I am looking the source code of ehci-irq, but I cannot see any >>> information which it will pass to "port_connect_change" when it >>> receive PCD interrupt. >>> if someone is familiar with this part of flow, please let me know. >>> appreciate your help, >> >> When ehci_irq() receives a PCD interrupt, it sets pcd_status and >> therefore calls usb_hcd_poll_rh_status(). That routine calls >> ehci_hub_status_data(), which reads the port status registers from the >> controller. The value is masked with PORT_CSC (Connect Status Change) >> causing a bit to be set in buf[0] or buf[1]. This bit tells the hub >> driver that a status change has occurred. >> > Thanks for your kind help :) > I did see what you mention in source code. > But the mechanism seems different in older version driver, which > ehci-irq doesn't set any flag but later time I can see someone wake up > hub driver to continue. sorry for not mentioning the version I saw, it is 2.6.20. thanks a lot, vichy -- 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
