Re: [PATCH v11 2/5] usb: renesas-xhci: Add the renesas xhci driver

[Greg Kroah-Hartman]

On Thu, Apr 30, 2020 at 08:56:50PM +0530, Vinod Koul wrote:
> On 30-04-20, 16:53, Greg Kroah-Hartman wrote:
> > On Thu, Apr 30, 2020 at 08:16:41PM +0530, Vinod Koul wrote:
> > > > > diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
> > > > > index b191361257cc..c3a79f626393 100644
> > > > > --- a/drivers/usb/host/Makefile
> > > > > +++ b/drivers/usb/host/Makefile
> > > > > @@ -70,7 +70,8 @@ obj-$(CONFIG_USB_OHCI_HCD_DAVINCI)	+= ohci-da8xx.o
> > > > >  obj-$(CONFIG_USB_UHCI_HCD)	+= uhci-hcd.o
> > > > >  obj-$(CONFIG_USB_FHCI_HCD)	+= fhci.o
> > > > >  obj-$(CONFIG_USB_XHCI_HCD)	+= xhci-hcd.o
> > > > > -obj-$(CONFIG_USB_XHCI_PCI)	+= xhci-pci.o
> > > > > +usb-xhci-pci-objs		:= xhci-pci.o xhci-pci-renesas.o
> > > > > +obj-$(CONFIG_USB_XHCI_PCI)	+= usb-xhci-pci.o
> > > > 
> > > > I don't think it's a good idea to rename the xhci-pci module to usb-xhci-pci
> > > > 
> > > > does
> > > > 
> > > > xhci-pci-y			:= xhci-pci.o xhci-pci-renesas.o
> > > > obj-$(CONFIG_USB_XHCI_PCI)	+= xhci-pci.o
> > > > 
> > > > cause some kbuild issues?
> > > 
> > > Yes with this version I get the warning:
> > > make[4]: Circular drivers/usb/host/xhci-pci.o <- drivers/usb/host/xhci-pci.o dependency dropped.
> > > 
> > > I don't speak enough Kbuild, but I guess it does make sense that we have
> > > xhci-pci.o as target for both xhci-pci.o xhci-pci-renesas.o! That was
> > > the reason for adding usb tag to this to resolve the conflict.
> > > 
> > > I am okay for any other mechanism which can work well here. Btw what
> > > issues do you foresee with adding usb tag to module name.
> > 
> > It will break all sorts of things.  Happens every time we rename
> > modules, let's not do it unless we absolutely have to.
> 
> Hmm that is interesting, am not sure why though :)

Module parameters, blacklists, init scripts, you name it.  Lots of them
default to module names and do not only look at the pci ids that modules
consist of after the system is originally set up.

> Anyway, I have fixed it up and was able to make both as modules and
> export two symbols for xhci-pci.ko to use :)

great.

thanks,

greg k-h