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

[Markus Armbruster]

Programmingkid <address@hidden> writes:

> 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. 

Yes, "info usb" doesn't show the qdev ID.  Neither does "info pci".
"info qom" and "info qtree" do.