Joel, On Wed, Oct 24, 2018 at 07:19:01PM +0200, Josep M. Mirats Tur wrote: > Hi Joel, > > The camera I have provides 640x480 as its lowest resolution. > Hope the issue can be solved. If your issue was same as mine - the uvc layer holds spinlock for too long in urb->complete() which prevents musb to schedule next IN transaction on time, it won't be that easy to solve. :( I had a try last year, but the solution caused other problem, then haven't looked at this issue since then. Regards, -Bin. > Regards > > On Wed, Oct 24, 2018 at 5:31 PM Joel Pepper <joel.pepper@xxxxxxxxxxxxxx> wrote: > > > > Hi Joseph, Hi Bin, > > > > I am currently investigating a bug with the BeagleBoneBlack (which also > > uses the AM335x) and a Logitech Webcam, which might be connected. > > > > I am using a Logitech C270 and if I set the format to YUYV and the > > framesize to 544x288 or larger (including specifically 640x480), any > > ioctl VIDIOC_DQBUF will hang indefinetely. This might be the underlying > > source of the timeout Joseph encountered. > > > > Joseph, > > > > have you tried setting the camera to the lowest resolution it can go? If > > low resolutions work, but higher ones, like 640x480 don't, we might be > > chasing the same problem. If not, I will look into my problem separately > > and open a new thread. > > > > > > Bin, > > > > my case happened using ISOC transfers, but my preliminary investigation > > has shown lots of ISOC traffic flowing, apparently successfuly from the > > camera to the BBB, which makes me suspect a problem closer to the > > v4l2/musb boundary, but I'm still reading into the code. If you would > > like to investigate that further, the C270 is rather affordable, but I > > will gladly provide any details, usbmon captures etc. that you require. > > > > > > Cheers, > > > > Joel Pepper > > > > On 19.10.2018 20:06, Josep M. Mirats Tur wrote: > > > Hi Bin, > > > > > >> Do you know what is the usb throughput required in your test case? for > > >> example image format, resolution, frame rate? Is the usb data transfer > > >> bulk or isoch? > > > Yes, the image format is 640 x 480 > > > The camera can run up to 30fps, although I do not need it and set up it to 5 > > > The Usb data transfer is "bulk" > > > > > > Regards > > > Josep M. > > > > > > On Fri, Oct 19, 2018 at 8:01 PM Bin Liu <b-liu@xxxxxx> wrote: > > >> On Fri, Oct 19, 2018 at 07:48:20PM +0200, Josep M. Mirats Tur wrote: > > >>> Hi, > > >>> > > >>> Yes, this would be the link: > > >>> http://shop-orbbec3d-com.3dcartstores.com/Astra-Mini_p_40.html > > >> Okay, It is about $160, a bit more than my bugdet... > > >> > > >>> In the meanwhile I'll check my application with other board. > > >>> > > >>> Do you think there might be a problem with the processor frequency? > > >>> I've also crossing e-mails with ORBBEC engineers, and their only > > >>> answer has been to suggest using an ARM processor capable of 1.8GHz > > >>> Beagle is capable of 1GHz > > >>> But I can not see why is this so important as long as USB is well > > >>> synchronized and interrupts and driver work well. (Actually I'm not > > >>> familiar with ARM USB system, is just intuition) > > >> I guess the cpu clock requirement is only to ensure the whole system is > > >> capable to process the usb packets, depending on the image resolution, > > >> fps, and any other data processing. But lower cpu clock shouldn't cause > > >> such problem that the usb controller generates rx interrupt but fifo has > > >> no usb packet. If ARM cannot keep up, which doesn't send IN requests on > > >> time, the camera should just drop data. > > >> > > >> Do you know what is the usb throughput required in your test case? for > > >> example image format, resolution, frame rate? Is the usb data transfer > > >> bulk or isoch? > > >> > > >> Regards, > > >> -Bin. > > > >
