Hi Chuanbo, On Friday 27 December 2013 09:55:40 Chuanbo Weng wrote: > > Hi all, > > > > (My environment is intel platform, HD4000 GPU, kernel 3.10.19, logitech > > 270 webcam) > > > > As title said, I discover this issue when I run the program shown by > > Laurent Pinchart: > > http://www.mail-archive.com/linux-media@xxxxxxxxxxxxxxx/msg54806.html > > > > If the frame is (width, height) = (640, 480), DMABUF works well. > > If the frame is (width, height) = (160, 120), v4lfd receives no event. > > > > And I dig into drm kernel code, find that: i915_gem_create will create a > > GPU buffer object on intel platform. The size of GPU bo will be bigger > > than frame size, for the reason that i915_gem_create will roundup the bo > > size to multiple of PAGE_SIZE when the frame is (width, height) = (160, > > 120). For (width, height) = (640, 480), the frame size is already multiple > > of PAGE_SIZE, so GPU bo is exactly equal to frame size. That should in theory not be an issue). This might be a stupid question, but have you tried to capture 160x120 images directly (with yavta for instance) without using DMABUF ? > > I also dump the uvc driver infomation, there is some infomation i > > think maybe important: > > uvcvideo: Stream 1 error event 07 01 len 4 > > > > Looking forward to the discussion! -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
