On Fri, Mar 04, 2016 at 03:17:30AM +0100, Andrew Lunn wrote: > > > > diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c > > > > index 053bac9..55120ef 100644 > > > > --- a/drivers/usb/chipidea/host.c > > > > +++ b/drivers/usb/chipidea/host.c > > > > @@ -109,15 +109,25 @@ static int host_start(struct ci_hdrc *ci) > > > > struct ehci_hcd *ehci; > > > > struct ehci_ci_priv *priv; > > > > int ret; > > > > + struct device *dev = ci->dev; > > > > > > > > - if (usb_disabled()) > > > > + if (usb_disabled() || !dev) > > > > return -ENODEV; > > > > > > > > - hcd = usb_create_hcd(&ci_ehci_hc_driver, ci->dev, > > > > dev_name(ci->dev)); > > > > + /* > > > > + * USB Core will try to get child node under roothub, > > > > + * but chipidea core has no of_node, and the child node > > > > + * for controller is located at glue layer's node which > > > > + * is chipidea core's parent. > > > > + */ > > > > + if (dev->parent && dev->parent->of_node) > > > > + dev->of_node = dev->parent->of_node; > > > > > > Is this a good idea? Two devices with the same of_node? > > > > > > > This is only for chipidea driver whose host controller device > > doesn't have entry at dts, but other host controller driver which > > supports device tree should have its entry at dts. > > > > > I know the networking code assumes of_node values are unique, and uses > > > it to find a device. Are you 100% sure the USB code does not make this > > > assumption. > > > > > > > The controller device is the root for USB device, the common > > USB code will not touch its glue layer device (controller's parent). > > I'm just thinking about code like: > > of_find_spi_master_by_node(), of_find_net_device_by_node(), > of_find_backlight_by_node(), etc. > > If somebody was to implement an of_find_usb_host_by_node() are you > 100% sure the right node will be found? This seems like a bug waiting > to happen.
Yes, almost 100% sure it is ok since the common USB code will never use its root's parent node to match or get something. -- Best Regards, Peter Chen -- 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
