On Tue, May 30, 2017 at 06:25:52PM +0200, Johan Hovold wrote:
> In an attempt to work around a pinmux over-allocation issue in driver
> core, commit dc5878abf49c ("usb: core: move root hub's device node
> assignment after it is added to bus") moved the device-tree node
> assignment until after the root hub had been registered.
>
> This not only makes the device-tree node unavailable to the usb driver
> during probe, but also prevents the of_node from being linked to in
> sysfs and causes a race with user-space for the (recently added) devspec
> attribute.
>
> Use the new device_set_of_node_from_dev() helper to reuse the node of
> the sysdev device, something which now prevents driver core from trying
> to reclaim any pinctrl pins during probe.
>
> Fixes: dc5878abf49c ("usb: core: move root hub's device node assignment after it is added to bus")
> Fixes: 51fa91475e43 ("usb/core: Added devspec sysfs entry for devices behind the usb hub")
> Signed-off-by: Johan Hovold <[email protected]>
> ---
> drivers/usb/core/hcd.c | 2 --
> drivers/usb/core/usb.c | 4 ++--
> 2 files changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> index 5dea98358c05..2cff59e9c268 100644
> --- a/drivers/usb/core/hcd.c
> +++ b/drivers/usb/core/hcd.c
> @@ -1076,7 +1076,6 @@ static void usb_deregister_bus (struct usb_bus *bus)
> static int register_root_hub(struct usb_hcd *hcd)
> {
> struct device *parent_dev = hcd->self.controller;
> - struct device *sysdev = hcd->self.sysdev;
> struct usb_device *usb_dev = hcd->self.root_hub;
> const int devnum = 1;
> int retval;
> @@ -1123,7 +1122,6 @@ 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 = sysdev->of_node;
> }
> mutex_unlock(&usb_bus_idr_lock);
>
> diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
> index 62e1906bb2f3..17681d5638ac 100644
> --- a/drivers/usb/core/usb.c
> +++ b/drivers/usb/core/usb.c
> @@ -416,8 +416,7 @@ static void usb_release_dev(struct device *dev)
>
> usb_destroy_configuration(udev);
> usb_release_bos_descriptor(udev);
> - if (udev->parent)
> - of_node_put(dev->of_node);
> + of_node_put(dev->of_node);
> usb_put_hcd(hcd);
> kfree(udev->product);
> kfree(udev->manufacturer);
> @@ -616,6 +615,7 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent,
> dev->route = 0;
>
> dev->dev.parent = bus->controller;
> + device_set_of_node_from_dev(&dev->dev, bus->sysdev);
> dev_set_name(&dev->dev, "usb%d", bus->busnum);
> root_hub = 1;
> } else {
> --
> 2.13.0
I am OK with it, but I suggest adding it for new rc1 since it is based
on the 1st patch which is a bug-fix. If this one is really needed for
stable tree in future, you can cherry-pick it.
--
Best Regards,
Peter Chen
On Mon, Jun 05, 2017 at 12:51:04PM +0800, Peter Chen wrote:
> On Tue, May 30, 2017 at 06:25:52PM +0200, Johan Hovold wrote:
> > In an attempt to work around a pinmux over-allocation issue in driver
> > core, commit dc5878abf49c ("usb: core: move root hub's device node
> > assignment after it is added to bus") moved the device-tree node
> > assignment until after the root hub had been registered.
> >
> > This not only makes the device-tree node unavailable to the usb driver
> > during probe, but also prevents the of_node from being linked to in
> > sysfs and causes a race with user-space for the (recently added) devspec
> > attribute.
> >
> > Use the new device_set_of_node_from_dev() helper to reuse the node of
> > the sysdev device, something which now prevents driver core from trying
> > to reclaim any pinctrl pins during probe.
> >
> > Fixes: dc5878abf49c ("usb: core: move root hub's device node assignment after it is added to bus")
> > Fixes: 51fa91475e43 ("usb/core: Added devspec sysfs entry for devices behind the usb hub")
> > Signed-off-by: Johan Hovold <[email protected]>
> I am OK with it, but I suggest adding it for new rc1 since it is based
> on the 1st patch which is a bug-fix. If this one is really needed for
> stable tree in future, you can cherry-pick it.
I agree, and didn't intent for this one to go into 4.12-rc. Let's see
how Greg wants to handle this. I'll add some comments to the cover
letter in v2.
Thanks,
Johan