[Qemu-devel] USB support

[Marek Zelem]

    Hi

I want to inform you that I successfully attached my Canon MP830
(printer, scanner, fax) to Qemu via USB.
It was not easy, I had to pass though two stoppages.

1. There is no support for multi port/config (do not know proper term
for that) USB devices in Qemu. Meaning that if single USB device
provides multiple functionalities (like printer, scanner, fax) it will
be rejected by Qemu.
Fortunately there is patch for that available on internet page
http://www.wina.at/uni/html/linux-qemu.html
(qemu-0.9.0-usb-multi-configs.patch).

2. When I applied the patch I hit another issue. When the USB device is
not ready it is automatically switched to HALT state (if I understood it
correctly) and additional ioctl USBDEVFS_CLEAR_HALT is required to give
device another chance. Thus, I have written patch for that issue. The
patch I am sending as attachment.

When I applied both patches, everything worked fine. I suggest to
include those two patches in Qemu.

Best regards

Marek Zelem

--
  e-mail: address@hidden
  web: http://marek.terminus.sk/
  pgp key: http://marek.terminus.sk/gpg.txt

--- usb-linux.c.orig    2008-01-12 12:56:09.000000000 +0100
+++ usb-linux.c 2008-01-12 14:02:47.000000000 +0100
@@ -229,12 +229,14 @@
     if (ret < 0) {
         switch(errno) {
         case ETIMEDOUT:
+           ret = ioctl(s->fd, USBDEVFS_CLEAR_HALT, &(bt.ep));
             return USB_RET_NAK;
         case EPIPE:
         default:
 #ifdef DEBUG
             printf("handle_data: errno=%d\n", errno);
 #endif
+           ret = ioctl(s->fd, USBDEVFS_CLEAR_HALT, &(bt.ep));
             return USB_RET_STALL;
         }
     } else {