On Thu, Jul 21, 2016 at 05:20:12PM +0800, Peter Chen wrote: > On Thu, Jul 21, 2016 at 10:14:38AM +0100, Russell King - ARM Linux wrote: > > On Wed, Jul 20, 2016 at 05:40:28PM +0800, Peter Chen wrote: > > > diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c > > > index 69426e6..0d05812 100644 > > > --- a/drivers/usb/chipidea/core.c > > > +++ b/drivers/usb/chipidea/core.c > > > @@ -914,6 +914,16 @@ static int ci_hdrc_probe(struct platform_device *pdev) > > > if (!ci) > > > return -ENOMEM; > > > > > > + /* > > > + * At device tree, we have no device node for chipidea core, > > > + * the glue layer's node is the parent node for host and udc > > > + * device. But in related driver, the parent device is chipidea > > > + * core. So, in order to let the common driver get parent's node, > > > + * we let the core's device node equals glue layer's node. > > > + */ > > > + if (dev->parent && dev->parent->of_node) > > > + dev->of_node = dev->parent->of_node; > > > > This is a dangerous thing to do. You're changing the dev->of_node of > > _this_ device, which means that _this_ driver will no longer match > > the device if you remove and reinsert the driver module, or unbind > > and try to re-bind the device to this driver. > > > > Thanks for commenting it. > > I have tested load/unload, it does not show any problems. > > The chipidea core device is created by code at runtime, not by device node. > And we have NO device node for this chipidea core device at dts. Okay, so we still probably have the bind/unbind problem, where "dev" can be matched by the driver which claimed "dev->parent". Remember, in an OF environment, driver matching is done by the compatible property, which is accessed via dev->of_node. Therefore, I would suggest that you NULL dev->of_node in the error cleanup paths and in the remove function, so you don't have an unbound device with a duplicated (but inappropriate) dev->of_node pointer. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
