On Thursday, September 8, 2016 8:28:10 PM CEST Peter Chen wrote: > On Thu, Sep 08, 2016 at 12:17:21PM +0200, Arnd Bergmann wrote: > > On Thursday, September 8, 2016 12:43:06 PM CEST Felipe Balbi wrote: > > > Arnd Bergmann <arnd@xxxxxxxx> writes: > > > > On Thursday, September 8, 2016 11:29:04 AM CEST Felipe Balbi wrote: > > > If we have a parent device, use that as sysdev, otherwise use self as > > > sysdev. > > > > But there is often a parent device in DT, as the xhci device is > > attached to some internal bus that gets turned into a platform_device > > as well, so checking whether there is a parent will get the wrong > > device node. > > From my point, all platform and firmware information at dwc3 are > correct, so we don't need to change dwc3/core.c, only changing for > xhci-plat.c is ok. Ok, thanks. That leaves the PCI glue, right? > diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c > index d2e3f65..563600b 100644 > --- a/drivers/usb/core/hcd.c > +++ b/drivers/usb/core/hcd.c > @@ -1118,7 +1118,7 @@ static int register_root_hub(struct usb_hcd *hcd) > /* Did the HC die before the root hub was registered? */ > if (HCD_DEAD(hcd)) > usb_hc_died (hcd); /* This time clean up */ > - usb_dev->dev.of_node = parent_dev->of_node; > + usb_dev->dev.of_node = parent_dev->sysdev->of_node; > } > mutex_unlock(&usb_bus_idr_lock); > > At above changes, the root hub's of_node equals to xhci-hcd sysdev's > of_node, which is from firmware or from its parent (it is dwc3 core > device). Just to make sure I understand you right: in the qcom,dwc3 -> dwc3 -> xhci hierarchy, this would be the dwc3 device, not the qcom,dwc3 device. > > > > That sounds a bit clumsy for the sake of consistency with PCI. > > > > The advantage is that xhci can always use the grandparent device > > > > as sysdev whenever it isn't probed through PCI or firmware > > > > itself, but the purpose of the dwc3-glue is otherwise questionable. > > > > > > > > How about adding a 'compatible="snps,dwc3-pci"' property for the dwc3 > > > > device when that is created from the PCI driver and checking for that > > > > with the device property interface instead? If it's "snps,dwc3" > > > > we use the device itself while for "snps,dwc3-pci", we use the parent? > > > > > For pci glue device, it is always the parent for dwc3 core device. > In your patch, you may not need to split pci or non-pci, just using > if (dev->parent). Here we have the pci-dwc3 -> dwc3 -> xhci hierarchy, and we want sysdev to point to pci-dwc3, not dwc3! The point is that the pci_dev is where we have the dma settings and (optionally) additional DT or ACPI data for that device. Arnd -- 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
