Re: [Qemu-devel] Large USB patch

[Fabrice Bellard <fabrice@bellard.org>]

Hi,

Could you make a small patch containing just the bug fixes of the state 
machine ?

Concerning your API changes, I am relunctant to include them now, but my 
mind can evolve. An API change that I would consider as very useful 
could be to be able to make asynchronous USB I/Os to avoid blocking QEMU 
while doing host USB I/Os.

Regards,

Fabrice.

nix.wie.weg@gmx.de wrote:
> Hello everybody,
> 
> I have extended the USB support for Qemu. The patch is included and
> compiles just fine against todays cvs repository. As explained below,
> this patch touches 15 different files, which makes it not so easy to
> keep it applying on that very fast developing project. Thats why I would
> ask you to test it quickly and apply it to cvs as soon as possible.
> 
> With this patch applied I could detect a USB Epson Scanner and a USB
> Epson Printer from Windows 98 + XP and I could even print pages with
> the printer (see known problems below).
> 
> reasons for this patch:
> I was looking for a way to address my USB printer with windows while
> working on linux. As I started the work I had to recognize that my
> printer was not even detected under qemu. So I started to work on it.
> 
> changes I made:
> First I eliminated all potential error sources, which could be avoided.
> One of these sources where the
> 
> 1. usb-hub - which I transfered to an extra file usb-hub.c, then I
> added the usb-libusb.c devices directly to the UHCI controller this
> introduced the changes of 2)
> 2. I enhanced the usb add device potentialities so that you should be
> able to add a device to the UHCI controller. This device can be a usb
> hub or a usb device. Behind this device you can add another hub or
> device ... (remember this feature is now theoretically possible but not
> tested yet), this let to a new usb syntax:
> #$ qemu -usb controller=uhci,busnum=001 device=host:2:3,addto=001:001
> (the short form is:
> #$ qemu -usb controller=uhci -usb device=host:2:3)
> so you can build up a complete usb tree.
> 3. I changed the usb_generic_handle_packet() function and implemented a
> state machine, which is able to handle the usb packets correct.
> 4. I changed the linux standard usb-host library to libusb. I personally
> will always prefer a portable solution if possible.
> 5. I changed large parts of usb-libusb.c. Some changes were made because
> I found the source very awkward, some others because I fixed errors and
> some because I changed the general usb api (see item 2).
> 6. I tried to join as many usb functions as possible to the usb related
> files. So that hopefully nobody has to change 15 files again.
> 7. I made minor changes to usb-uhci - mainly I applied the new api and
> changed the handling of special messages like usb_reset or usb_attach
> 8. I made the necessary changes to usb-hid.c and usb-hub.c
> 9. I wrote a lot of source comments
> 
> this patch breaks some things:
> Sorry guys but I could not fix all of it, so I need your help, I didn't
> want to destroy anybodys work, but the new api makes it necessary to
> change some files:
> 1. usb-linux.c and usb-bsd.c will not work without adoption of the new api
> 2. I did not test usb-hid and usb-hub
> 
> known problems:
> 1. under linux the uhci controller reports an error if no usb device is
> connected
> 2. the printer and the scanner are recognized under Windows 98/XP and
> Linux, but the scanner goes into STALL state as soon as a packet in
> usb_write_bulk() or usb_read_bulk()
> 3. the libusb usb_host_reset() function does not work as expected and I
> don't know why (i have commented out this part of the source)
> 4. the printer stops printing on large images and is then in a state,
> where it will not resume his work (probably a timing issue)
> 
> With kind regards,
> Tino H. Seifert
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> Qemu-devel mailing list
> Qemu-devel@nongnu.org
> http://lists.nongnu.org/mailman/listinfo/qemu-devel