Re: [Qemu-devel] [PATCH RFT 0/5] usb: Clean up and extend SysBus EHCI

[walimis <walimisdev@gmail.com>]

On Mon, Dec 03, 2012 at 12:10:02PM +0000, Peter Maydell wrote:
>On 3 December 2012 11:58, walimis <walimisdev@gmail.com> wrote:
>> For example, xilinx_zynq has two EHCI controllers. If I specify a usb
>> device of type "usb-storage", the question is: which EHCI controller does the
>> usb device attach to? The answer is dependent.
>>
>> 1. If I use "usbdevice" and pass the host usb device, such as:
>>
>> $ qemu -usb  -usbdevice host:xxxx:xxxx
>>
>> The device will attach to the first EHCI controller.
>>
>> 2. If I use "device" and "usb-storage", such as:
>>
>> $ qemu -usb -device usb-storage,drive=ud -drive id=ud,file=usbdisk.img,if=none
>>
>> The device will attach to the second EHCI controller.
>
>This is a long standing bug which is caused by the legacy
>-usbdevice search looking through the list of usb buses
>in one direction, and the generic -device code looking
>through it in the other direction:
>
>http://lists.gnu.org/archive/html/qemu-devel/2011-06/msg00926.html
>
>> Qemu doesn't provide some properties, such as "bus", to specify which EHCI controller the
>> usb device attach to.  If we use "device" and "usb-storage", we never attach the usb
>> device to the specified EHCI controller.
>
>-device certainly ought to let you specify a bus= property;

Sorry, I don't know the bus= property. 
But why both EHCI controller are named "usb-bus.0"? How to distinguish the
different usb usb?

Liming Wang

>you want to be able to specify the USB controller regardless
>of whether we sort out the ordering mess. If that doesn't
>work then we have a different bug.
>
>-- PMM