Linux kernel stable tree (mirror) https://git.radix-linux.su/kernel/linux.git/atom?h=v6.19.11 2016-07-18T06:54:55+00:00 2016-07-18T06:54:55+00:00 Chris Wilson chris@chris-wilson.co.uk 2016-07-15T08:31:11+00:00 urn:sha1:4077798484459a2eced2050045099a466ecb618a vGEM buffers are useful for passing data between software clients and hardware renders. By allowing the user to create and attach fences to the exported vGEM buffers (on the dma-buf), the user can implement a deferred renderer and queue hardware operations like flipping and then signal the buffer readiness (i.e. this allows the user to schedule operations out-of-order, but have them complete in-order). This also makes it much easier to write tightly controlled testcases for dma-buf fencing and signaling between hardware drivers. v2: Don't pretend the fences exist in an ordered timeline, but allocate a separate fence-context for each fence so that the fences are unordered. v3: Make the debug output more interesting, and show the signaled status. v4: Automatically signal the fence to prevent userspace from indefinitely hanging drivers. Testcase: igt/vgem_basic/dmabuf-fence Testcase: igt/vgem_slow/nohang Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Sean Paul <seanpaul@chromium.org> Cc: Zach Reizner <zachr@google.com> Cc: Gustavo Padovan <gustavo.padovan@collabora.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Zach Reizner <zachr@google.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1468571471-12610-1-git-send-email-chris@chris-wilson.co.uk