On 08/28/2017 06:00 AM, Mathias Nyman wrote:
On 19.07.2017 01:39, Curt Meyers wrote:
Hello,
I have a new USB3 camera that can only operate in isochronous mode. I
can open and stream data from the camera using guvcview. The camera
has 3 interfaces, two show up as uvc video devices. The interface I
open claims a maximum bandwidth dwMaxBitRate=73728000, I should be
able to open many of these devices on a USB3 interface based on
bandwidth.
If I try to open 2 or more devices on any hardware except one
particular computer it fails and I get the message:
[ 6345.752365] usb 2-2: Not enough bandwidth for new device state.
[ 6345.752368] usb 2-2: Not enough bandwidth for altsetting 2
On the working computer I have run up to 5 devices from a single xhci
controller and a hub without any problem, it ran for hours. The
working computers belongs to someone else and has an i7-3770
processor (3rd generation). The failing computers are all more modern
and contain an i7-6600U, i3-7700 and an E5-2620v3 with various
supporting chipsets, the one I am concerned with is a:
00:14.0 USB controller: Intel Corporation Sunrise Point-H USB 3.0
xHCI Controller (rev 31)
Initially this started on a 4.4 kernel, then I upgraded to 4.8 and it
still fails. I got the owner of the working machine to upgrade to 4.8
and it still works. Then I fetched and built 4.13 from the "next"
branch. I have poked around in the uvc code and in the xhci code and
I can't really get a handle on what is going on. I tried to force
some different alternate settings, I have modified the uvc code to
fix other "quirky" cameras in the past but nothing seems to make any
improvements here.
I am looking for suggestions on what I can try next. I am attaching
the output from the usb device descriptor, this is a stereo camera
that outputs depth data on the second interface, to the 320x480
resolution is really the depth of two pixels packet together. It is
this resolution that I am trying to run but all resolutions basically
fail.
xhci configure endpoint command returned with a bandwidth, or
secondarty bandwidth error
because xHC hardware can't fulfill the bandwidth requested in xhci
endpoint context structure.
xhci endpoint context is filled with slightly modified values from the
endpoint descriptor
(like wMaxPacketSize, bInterval, bMaxBurst and Mult fields)
New kernel have tracing for the endpoint context, First thing would
probably be to check that the endpoint context look sane.
xhci tracing will generate a lot of data, It can be enabled with:
mount -t debugfs none /sys/kernel/debug
echo 81920 > /sys/kernel/debug/tracing/buffer_size_kb
echo 1 > /sys/kernel/debug/tracing/events/xhci-hcd/enable
Then send me the content of
/sys/kernel/debug/tracing/trace
Thanks
Mathias
Did the log file I sent make any sense?
I sent it only to you, didn't want to email it through the list server.
Curt
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