On Thu, 29 Jan 2015, Peter Chen wrote: > > > Then, it is strange. Do we need even two glue layer drivers for pci > > > device? Look at usb/chipidea/ci_hdrc_pci.c it has pci_register_driver, > > > and its host driver will call ehci_init_driver, it is definitely > > > duplicated with usb/host/ehci-pci.c. > > > > ehci-pci.c is a driver for a USB Host Controller, whereas ci_hdrc_pci.c > > is a driver for a USB Device Controller. > > > > In fact, it is not, ci_hdrc_pci is the pci glue layer for chipidea > driver. I am just wonder andy's v2 change is suitable or not, the > right way should not call ehci_pci_init at all.
The chipidea driver is structured in an odd way. It looks like the PCI device combines a host controller and a device controller (and maybe even an OTG controller) into a single device. That's why the chipidea driver has to duplicate ehci-pci.c and register various platform devices. If ehci-pci were allowed to bind to the device then the gadget controller (and OTG controller?) would be unusable, because ehci-pci doesn't know how to use them. 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
