Hi Nicolas, On Tue, Oct 10, 2017 at 11:40:10AM -0400, Nicolas Dufresne wrote: > Le mardi 29 août 2017 à 14:26 +0300, Stanimir Varbanov a écrit : > > Currently videobuf2-dma-sg checks for dma direction for > > every single page and videobuf2-dc lacks any dma direction > > checks and calls set_page_dirty_lock unconditionally. > > > > Thus unify and align the invocations of set_page_dirty_lock > > for videobuf2-dc, videobuf2-sg memory allocators with > > videobuf2-vmalloc, i.e. the pattern used in vmalloc has been > > copied to dc and dma-sg. > > Just before we go too far in "doing like vmalloc", I would like to > share this small video that display coherency issues when rendering > vmalloc backed DMABuf over various KMS/DRM driver. I can reproduce this > easily with Intel and MSM display drivers using UVC or Vivid as source. > > The following is an HDMI capture of the following GStreamer pipeline > running on Dragonboard 410c. > > gst-launch-1.0 -v v4l2src device=/dev/video2 ! video/x-raw,format=NV16,width=1280,height=720 ! kmssink > https://people.collabora.com/~nicolas/vmalloc-issue.mov > > Feedback on this issue would be more then welcome. It's not clear to me > who's bug is this (v4l2, drm or iommu). The software is unlikely to be > blamed as this same pipeline works fine with non-vmalloc based sources. Could you elaborate this a little bit more? Which Intel CPU do you have there? Where are the buffers allocated for this GStreamer pipeline, is it v4l2src or another element or somewhere else? -- Kind regards, Sakari Ailus e-mail: sakari.ailus@xxxxxx
