once more with a webcam issue.
It appears that the newer Angstrom distros for the Beaglebone (certainly 2012.05.09) disable DMA, which is to fix a bug with iso transfers over USB. The problem is that now the code I have to get images from my webcams (Trust Spotlight and Venus USB2.0) doesn’t work at all.
The code I have uses memory-mapped buffers and immediately returns a “select timeout” when I try to grab an image; I assume this happens as a result of DMA being disabled. I know the code itself worked, because on the 2012.02.14 Angstrom distro (which was DMA-enabled) I could get images from the webcams, at least until some iso bug transfer showed up and halted reception.
Unfortunately, read/write transfers aren’t supported by either of my two webcams.
So the questions are,
has anyone obtained a reliable stream of data from webcams on the newer Angstrom for Beaglebone distributions? Reliable means that, unlike older distros, “select timeout” errors do not appear.
if you did get a reliable stream, what kind of data transfer did you use and what webcam?
Thanks in advance!