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

[Programmingkid]

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. 

> 
>>                                                   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".