Re: [Qemu-devel] qemu-doc.texi: Improve USB documentation... and maybe even QEMU also

[Programmingkid]

On Aug 24, 2015, at 12:38 PM, Markus Armbruster wrote:

> Programmingkid <address@hidden> writes:
> 
>> On Aug 24, 2015, at 5:45 AM, Markus Armbruster wrote:
>> 
>>> Copying the USB maintainer.
>>> 
>>> Programmingkid <address@hidden> writes:
>>> 
>>>> On Aug 8, 2015, at 8:48 AM, Programmingkid wrote:
>>>> 
>>>>> 
>>>>> On Aug 8, 2015, at 2:04 AM, Markus Armbruster wrote:
>>>>>>> 
>>>>>>> USB devices can be connected with the @option{-usbdevice}
>>>>>>> commandline option
>>>>>>> -or the @code{usb_add} monitor command.  Available devices are:
>>>>>>> +or the @code{usb_add} monitor command. Note: some devices may
>>>>>>> only work if
>>>>>>> +added like this: -usb -device <usb device>. Available devices are:
>>>>>> 
>>>>>> I'm afraid "may only work" is a bit misleading.  All of them work with
>>>>>> -device.  Old ones are also supported by -usbdevice for backward
>>>>>> compatibility.  The whole section should be rewritten to point to
>>>>>> -device instead of legacy -usbdevice, but that's no reason to hold up
>>>>>> your patch.
>>>>> 
>>>>> I did not know -usbdevice was considered legacy. If that is the
>>>>> case, then it should probably
>>>>> be removed from the documentation in favor for -usb -device <device 
>>>>> name>. 
>>>> 
>>>> Right now using "-usb -device mouse" doesn't work.
>>> 
>>> You need to say -device usb-mouse.  See docs/qdev-device-use.txt.  Does
>>> it work for you when you do that?
>> 
>> It does. Thank you for this information. 
> 
> My pleasure.
> 
>>>>                                                  Neither does
>>>> "-usbdevice usb-audio".
>>> 
>>> Yes.  Legacy -usbdevice only supports the devices that predate -device.
>>> 
>>>> I think we can all agree that consistency among all the USB devices is
>>>> a good thing.
>>>> Should all USB devices be added like this: -usb -device <device name> ? 
>>> 
>>> "Should" is perhaps a bit strong.  While -device is the recommended way
>>> to add a USB device, -usbdevice is still a supported (if legacy) way to
>>> do it.
>>> 
>>> Of course, "supported, but legacy" interfaces such as -usbdevice may
>>> become deprecated, and then you should really move to newer interfaces,
>>> because deprecated ones may go away.  Doesn't look terribly probable to
>>> me for -usbdevice, though.
>>> 
>>>> This is an experimental patch of not how QEMU currently works, but how
>>>> I think it should work.
>>>> 
>>>> This documentation adds an "usb_remove" monitor command. This isn't
>>>> available right now,
>>>> but a patch could be made to change this. Any suggestions or additions
>>>> are welcomed.
>>> 
>>> Why do you think we need usb_remove in addition to device_del?
>> 
>> Ok. usb_remove isn't needed. Why is it that "device_add usb-kbd" works, but
>> "device_del usb-kbd" doesn't work? I am given this error message:
>> "Device 'usb-kbd' not found".
> 
> device_del's argument isn't a driver, it's a device ID.  Try this:
> 
>    (qemu) device_add usb-mouse,id=mouse0
>    (qemu) info usb
>      Device 0.0, Port 1, Speed 12 Mb/s, Product QEMU USB Mouse
>    (qemu) device_del mouse0
>    (qemu) info usb
>    (qemu) 

The problem is with "info usb". It doesn't print the id you gave it. I will 
make a patch that
will print the id's.