From: Diego Viola <diego.viola@gmail.com>
To: qemu-devel@nongnu.org
Subject: Re: Slow video output from webcam with qemu-xhci but smooth with usb-ehci
Date: Sun, 13 Dec 2020 16:30:47 -0300 [thread overview]
Message-ID: <CA+ToGPHFEsqwUmH-E8ZSkcsPa68dPnXmDBOJBqehev4RnC0t6A@mail.gmail.com> (raw)
In-Reply-To: <CA+ToGPHan_XHjy+=3vzefnJ9+EBHkL+BBR2FgM_v-XWcqVkgQw@mail.gmail.com>
Not sure it's related but I'm seeing this on the guest now when I use
mpv --vo=drm on a tty:
[ 28.918606] xhci_hcd 0000:00:04.0: ERROR Transfer event TRB DMA ptr
not part of current TD ep_index 2 comp_code 13
[ 28.919816] xhci_hcd 0000:00:04.0: Looking for event-dma
000000012a8c7d80 trb-start 000000012a8c7d70 trb-end 000000012a8c7d70
seg-start 000000012a8c7000 seg-end 000000012a8c7ff0
[ 28.919818] xhci_hcd 0000:00:04.0: ERROR Transfer event TRB DMA ptr
not part of current TD ep_index 2 comp_code 13
[ 28.921019] xhci_hcd 0000:00:04.0: Looking for event-dma
000000012a8c7d90 trb-start 000000012a8c7d70 trb-end 000000012a8c7d70
seg-start 000000012a8c7000 seg-end 000000012a8c7ff0
[ 28.921023] xhci_hcd 0000:00:04.0: ERROR Transfer event TRB DMA ptr
not part of current TD ep_index 2 comp_code 13
[ 28.922203] xhci_hcd 0000:00:04.0: Looking for event-dma
000000012a8c7da0 trb-start 000000012a8c7d70 trb-end 000000012a8c7d70
seg-start 000000012a8c7000 seg-end 000000012a8c7ff0
Video is then a bit smoother.
Diego
On Sat, Dec 12, 2020 at 1:28 PM Diego Viola <diego.viola@gmail.com> wrote:
>
> Hi,
>
> I'm experiencing a lot of choppiness in the video output when I pass
> through my USB webcam to the guest using qemu-xhci as follows:
>
> qemu-system-x86_64 -enable-kvm -hda arch-zoom.qcow2 -m 4G -vga virtio
> -device qemu-xhci,id=xhci -device
> usb-host,bus=xhci.0,hostdevice=/dev/bus/usb/002/004
>
> My webcam is:
>
> Bus 002 Device 004: ID 04f2:b449 Chicony Electronics Co., Ltd Integrated Camera
>
> I am using mpv /dev/video0 from the guest.
>
> It works fine if I use usb-ehci instead, e.g.:
>
> qemu-system-x86_64 -enable-kvm -hda arch-zoom.qcow2 -m 4G -vga virtio
> -device usb-ehci,id=ehci -device
> usb-host,bus=ehci.0,hostdevice=/dev/bus/usb/002/004
>
> In this case, the video output from mpv /dev/video0 is not choppy.
>
> My QEMU version is 5.2.0 -- I am running Arch Linux on the host and guest.
>
> Any ideas please?
>
> Thanks,
> Diego
next prev parent reply other threads:[~2020-12-13 19:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-12 16:28 Slow video output from webcam with qemu-xhci but smooth with usb-ehci Diego Viola
2020-12-13 19:30 ` Diego Viola [this message]
2020-12-13 19:42 ` Diego Viola
2020-12-13 22:46 ` Diego Viola
2020-12-17 20:24 ` Dr. David Alan Gilbert
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