Open BrianAdams opened 8 years ago
As of Kernel 4.1.8-ti-r18, we are still seeing issues regarding isochronous mode.
From the Raspi community: https://www.raspberrypi.org/forums/viewtopic.php?p=257512 https://github.com/raspberrypi/linux/issues/238#issuecomment-15261263 https://gist.github.com/P33M/5213278
BBB: http://lxr.free-electrons.com/source/drivers/usb/musb/musb_am335x.c?v=4.4
Todo
Follow up: It does not appear that the Genius camera uses DMA transfer. You can look at the interrupts and it is straight to the uvc driver, no DMA driver listed.
Did a side by side, the 30.0.1 release does not have a problem with the Genius camera. The dev releases with Kernel 4.4.19 Preempt RT (among others) most certainly do have an issue in the form of an insane number of interrupts. That said, even the 30.0.1 release has the issue with bright contrast causing the USB to freeze up.
https://e2e.ti.com/support/embedded/linux/f/354/t/332530#pi317016