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 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
