Re: [PATCH v5] USB: core: skip unconfiguration if device doesn't support it

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



>> Come to think of it, maybe there is a simple workaround.  If userspace
>> resets the device after it is unconfigured, there's a good chance that
>> will get it to start working again.  Jose, can you try this?  There is a
>> usbreset program you can use, floating around on the web.  (Greg, did
>> that program or something like it ever get added to the usbutils
>> package?)

> Yes, it is in the usbutils package.  I don't think many distros package
> the prebuilt binary, but the .c file can be found here:
>        https://github.com/gregkh/usbutils/blob/master/usbreset.c

Of course, I can also try that way and I will comment on the result.
I would like to identify in some way, I have some ideas related to the
initial configuration but I have to research more.
If not possible, if there is a user workaround like this, it would be great.

Thank you very much

José Ignacio

On Fri, May 13, 2022 at 4:46 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Fri, May 13, 2022 at 10:26:02AM -0400, Alan Stern wrote:
> > On Fri, May 13, 2022 at 04:13:07PM +0200, Greg KH wrote:
> > > On Fri, May 13, 2022 at 10:09:26AM -0400, Alan Stern wrote:
> > > > On Fri, May 13, 2022 at 11:50:26AM +0200, Jose Ignacio Tornos Martinez wrote:
> > > > > Ok, I will try to identify the "bad" devices in some way.
> > > > >
> > > > > Thanks
> > > > >
> > > > > José Ignacio
> > > > >
> > > > >
> > > > > On Thu, May 12, 2022 at 1:48 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> > > > > >
> > > > > > I'll drop this for now as there are no in-kernel users for this quirk
> > > > > > yet.  When there is a need for one, please resubmit it.
> > > >
> > > > Hold on; Greg's comment doesn't seem fair.  There are no in-kernel
> > > > users for this quirk because it is meant to be a user API.  (Just as
> > > > there are no in-kernel users for read(2) -- it is there so that
> > > > userspace can call it).
> > >
> > > True, but the kernel calls read(2) itself as well in places, it just
> > > looks a bit different, kernel_read_file()  :)
> >
> > Okay, but you get the point.  :-)
> >
> > > > Jose does have users for the new quirk: Anybody with one of the bad
> > > > Bluetooth CSR knockoff chips.  Now I agree; it would be great if there
> > > > was some way to identify them automatically.  But if that's not
> > > > possible, the only alternative is to allow userspace to set the quirk
> > > > flag whenever it knows the quirk is needed.
> > >
> > > Is that the case here that we know how to identify this?  I thought
> > > Marcel said something else was happening here.
> > >
> > > If the bluetooth developers/maintainers say this is needed for some
> > > devices to work properly and they will be handled in userspace somehow
> > > through a udev rule or the like, I will gladly add this.  But I thought
> > > this thread died out as it was determined that this wasn't needed at
> > > this point in time which is why I dropped it.
> >
> > It's kind of an odd situation.  In ordinary usage the device works okay.
> > But it stops working after it has been exported over usbip; that is what
> > Jose wants to fix.
> >
> > Come to think of it, maybe there is a simple workaround.  If userspace
> > resets the device after it is unconfigured, there's a good chance that
> > will get it to start working again.  Jose, can you try this?  There is a
> > usbreset program you can use, floating around on the web.  (Greg, did
> > that program or something like it ever get added to the usbutils
> > package?)
>
> Yes, it is in the usbutils package.  I don't think many distros package
> the prebuilt binary, but the .c file can be found here:
>         https://github.com/gregkh/usbutils/blob/master/usbreset.c
>





[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux