2023-06-13 09:58:04

by Jonas Blixt

Subject: [PATCH] USB: usbip: fix stub_dev hub disconnect

If a hub is disconnected that has device(s) that's attached to the usbip layer
the disconnect function might fail because it tries to release the port
on an already disconnected hub.

Fixes: 6080cd0e9239 ("staging: usbip: claim ports used by shared devices")
Signed-off-by: Jonas Blixt <[email protected]>
---
drivers/usb/usbip/stub_dev.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/usbip/stub_dev.c b/drivers/usb/usbip/stub_dev.c
index 2305d425e6c9..257861787cdf 100644
--- a/drivers/usb/usbip/stub_dev.c
+++ b/drivers/usb/usbip/stub_dev.c
@@ -427,8 +427,12 @@ static void stub_disconnect(struct usb_device *udev)
/* release port */
rc = usb_hub_release_port(udev->parent, udev->portnum,
(struct usb_dev_state *) udev);
- if (rc) {
- dev_dbg(&udev->dev, "unable to release port\n");
+ /*
+ * NOTE: If a HUB disconnect triggered disconnect of the down stream
+ * device usb_hub_release_port will return -ENODEV.
+ */
+ if (rc && (rc != -ENODEV)) {
+ dev_dbg(&udev->dev, "unable to release port (%i)\n", rc);
return;
}

--
2.25.1

2023-06-13 10:00:05

by Greg Kroah-Hartman

Subject: Re: [PATCH] USB: usbip: fix stub_dev hub disconnect

On Tue, Jun 13, 2023 at 11:29:18AM +0200, Jonas Blixt wrote:
> If a hub is disconnected that has device(s) that's attached to the usbip layer
> the disconnect function might fail because it tries to release the port
> on an already disconnected hub.
>
> Fixes: 6080cd0e9239 ("staging: usbip: claim ports used by shared devices")
> Signed-off-by: Jonas Blixt <[email protected]>
> ---
> drivers/usb/usbip/stub_dev.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/usbip/stub_dev.c b/drivers/usb/usbip/stub_dev.c
> index 2305d425e6c9..257861787cdf 100644
> --- a/drivers/usb/usbip/stub_dev.c
> +++ b/drivers/usb/usbip/stub_dev.c
> @@ -427,8 +427,12 @@ static void stub_disconnect(struct usb_device *udev)
> /* release port */
> rc = usb_hub_release_port(udev->parent, udev->portnum,
> (struct usb_dev_state *) udev);
> - if (rc) {
> - dev_dbg(&udev->dev, "unable to release port\n");
> + /*
> + * NOTE: If a HUB disconnect triggered disconnect of the down stream
> + * device usb_hub_release_port will return -ENODEV.

How about adding, "so we can safely ignore that error here."

thanks,

greg k-h

2023-06-15 09:49:45

by Jonas Blixt

Subject: Re: [PATCH] USB: usbip: fix stub_dev hub disconnect

On Tue, Jun 13, 2023 at 11:50:31AM +0200, Greg KH wrote:
> On Tue, Jun 13, 2023 at 11:29:18AM +0200, Jonas Blixt wrote:
> > If a hub is disconnected that has device(s) that's attached to the usbip layer
> > the disconnect function might fail because it tries to release the port
> > on an already disconnected hub.
> >
> > Fixes: 6080cd0e9239 ("staging: usbip: claim ports used by shared devices")
> > Signed-off-by: Jonas Blixt <[email protected]>
> > ---
> > drivers/usb/usbip/stub_dev.c | 8 ++++++--
> > 1 file changed, 6 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/usb/usbip/stub_dev.c b/drivers/usb/usbip/stub_dev.c
> > index 2305d425e6c9..257861787cdf 100644
> > --- a/drivers/usb/usbip/stub_dev.c
> > +++ b/drivers/usb/usbip/stub_dev.c
> > @@ -427,8 +427,12 @@ static void stub_disconnect(struct usb_device *udev)
> > /* release port */
> > rc = usb_hub_release_port(udev->parent, udev->portnum,
> > (struct usb_dev_state *) udev);
> > - if (rc) {
> > - dev_dbg(&udev->dev, "unable to release port\n");
> > + /*
> > + * NOTE: If a HUB disconnect triggered disconnect of the down stream
> > + * device usb_hub_release_port will return -ENODEV.
>
> How about adding, "so we can safely ignore that error here."
>
> thanks,
>
> greg k-h

Yes, I'll update the comment and prepare a V2 patch.

Jonas