ndufresne: no worries mchehab: about the usb dma from stack patch from Laurent Caumont you just replied to on linux-media, I'm happy to send a final version of the patch but since he wrote it won't it need his signed-off-by first? syoung: my understanding is that this is a joint work from you both. So, such patch should contain both SOBs yep I assume it would be included in v4.15 if possible it is a bug fix, so, if it can make in time, I'll try to add for 4.15 s/make/made/ sailus, btw, I saw your question, with the LinuxConn and work accumulating, I haven't had time to retest if the coherency issue is gone with CMA sailus, but reading through the dma API, and UVC/vivid driver, there should be some calls around the memcpy (uvc) and memory operation (vivid) which are missing at least that's seems to be a plausible reason