usb devices get redetected all the time in 2.6.0-test{7,9}

usb devices get redetected all the time in 2.6.0-test{7,9}

[Soeren Sonnenburg]

Hi.

When I attach a camera to a 2.4. based machine hotplug starts up some
script to download images of that camera and fine thats it.

In 2.6.0-testX I see kernel messages like:

hub 2-0:1.0: new USB device on port 1, assigned address 2
bus usb: add device 2-1
bound device '2-1' to driver 'usb'
bus usb: add device 2-1:1.0
bus usb: remove device 2-1:1.0
bus usb: add device 2-1:1.0
bus usb: remove device 2-1:1.0
bus usb: add device 2-1:1.0
bus usb: remove device 2-1:1.0
bus usb: add device 2-1:1.0
[...]

and several of these hotplug scripts get started... Is this a wanted
behaviour and something has to be fixed in userspace or is it a kernel
bug ?

Soeren

Re: usb devices get redetected all the time in 2.6.0-test{7,9}

[Greg KH]

On Wed, Oct 29, 2003 at 08:15:26AM +0100, Soeren Sonnenburg wrote:
> Hi.
> 
> When I attach a camera to a 2.4. based machine hotplug starts up some
> script to download images of that camera and fine thats it.
> 
> In 2.6.0-testX I see kernel messages like:
> 
> hub 2-0:1.0: new USB device on port 1, assigned address 2
> bus usb: add device 2-1
> bound device '2-1' to driver 'usb'
> bus usb: add device 2-1:1.0
> bus usb: remove device 2-1:1.0
> bus usb: add device 2-1:1.0
> bus usb: remove device 2-1:1.0
> bus usb: add device 2-1:1.0
> bus usb: remove device 2-1:1.0
> bus usb: add device 2-1:1.0
> [...]
> 
> and several of these hotplug scripts get started... Is this a wanted
> behaviour and something has to be fixed in userspace or is it a kernel
> bug ?

Does this settle down after a bit, or does the add/remove stuff keep
going on for a while?

Can you enable CONFIG_USB_DEBUG and see if you get any more information
in the kernel debug log as to why this is happening?

thanks,

greg k-h

Re: usb devices get redetected all the time in 2.6.0-test{7,9}

[Soeren Sonnenburg]

On Wed, 2003-10-29 at 21:01, Greg KH wrote:
> On Wed, Oct 29, 2003 at 08:15:26AM +0100, Soeren Sonnenburg wrote:
> > Hi.
> > 
> > When I attach a camera to a 2.4. based machine hotplug starts up some
> > script to download images of that camera and fine thats it.
> > 
> > In 2.6.0-testX I see kernel messages like:
> > 
> > hub 2-0:1.0: new USB device on port 1, assigned address 2
> > bus usb: add device 2-1
> > bound device '2-1' to driver 'usb'
> > bus usb: add device 2-1:1.0
> > bus usb: remove device 2-1:1.0
> > bus usb: add device 2-1:1.0
> > bus usb: remove device 2-1:1.0
> > bus usb: add device 2-1:1.0
> > bus usb: remove device 2-1:1.0
> > bus usb: add device 2-1:1.0
> > [...]
> > 
> > and several of these hotplug scripts get started... Is this a wanted
> > behaviour and something has to be fixed in userspace or is it a kernel
> > bug ?
> 
> Does this settle down after a bit, or does the add/remove stuff keep
> going on for a while?

I realized that when I disable the hotplug script the camera is detected
only once (as it should).

The script fetches the directory listing off the camera... thus is
probably opening+closing the device once. So I wonder whether this could
somehow trigger an usb disconnect on close() making the usb driver to
redetect the device ?!

> Can you enable CONFIG_USB_DEBUG and see if you get any more information
> in the kernel debug log as to why this is happening?

If still needed I will do.

Soeren