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From: | Arnon Gilboa |
Subject: | [Qemu-devel] [PATCH] Redirected USB devices isochronous support |
Date: | Tue, 11 Sep 2007 06:51:26 -0700 |
Attached
is a preliminary patch for supporting isochronous transfers in redirected host USB
devices. The initial goal was supporting USB 1.1 Webcam. Tested on several
Webcams. Works on USB 1.1 Webcams, as well as most USB 2.0 Webcams (backward
compatibility) on low resolutions. Some jitter is visible in the video stream,
and it will be fixed. Notice
USE_ASYNCIO, which defines whether to use signal based async io or polling for
receiving urbs. Currently it is disabled, so polling is used, but it does not
seem to affect the performance because it uses the non-blocking USBDEVFS_REAPURBNDELAY
ioctl. In order to use the signal based async io, a further patch to usb-uhci.c
will be posted. The
patch includes parts of previous patches posted in Qemu-devel: usb_host_update_interfaces
(from qemu-0.9.0-usb-multi-configs.patch), usb_linux_update_endp_table (qemu-usb-host-async.patch)
as well as some other lines of code. I am
starting to work on the ehci emulation for fully supporting USB 2.0 isochronous
devices. Waiting
for your comments, Arnon |
qemu-usb-isoch.patch
Description: qemu-usb-isoch.patch
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