Hi Daniel, Greg, If it is the same or a similar crash reported here: https://lists.freedesktop.org/archives/dri-devel/2021-November/330018.html and here: https://lists.freedesktop.org/archives/dri-devel/2021-November/330212.html then the fix is already merged: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d89c0c8322ecdc9a2ec84b959b6f766be082da76 Thanks, Vivek > On Sat, Nov 13, 2021 at 03:51:48PM +0100, Greg KH wrote: > > On Tue, Sep 21, 2021 at 04:20:23PM -0700, Gurchetan Singh wrote: > > > Similar to DRM_VMW_EVENT_FENCE_SIGNALED. Sends a pollable event > > > to the DRM file descriptor when a fence on a specific ring is > > > signaled. > > > > > > One difference is the event is not exposed via the UAPI -- this is > > > because host responses are on a shared memory buffer of type > > > BLOB_MEM_GUEST [this is the common way to receive responses with > > > virtgpu]. As such, there is no context specific read(..) > > > implementation either -- just a poll(..) implementation. > > > > > > Signed-off-by: Gurchetan Singh <gurchetansingh@xxxxxxxxxxxx> > > > Acked-by: Nicholas Verne <nverne@xxxxxxxxxxxx> > > > --- > > > drivers/gpu/drm/virtio/virtgpu_drv.c | 43 +++++++++++++++++++++++++- > > > drivers/gpu/drm/virtio/virtgpu_drv.h | 7 +++++ > > > drivers/gpu/drm/virtio/virtgpu_fence.c | 10 ++++++ > > > drivers/gpu/drm/virtio/virtgpu_ioctl.c | 34 ++++++++++++++++++++ > > > 4 files changed, 93 insertions(+), 1 deletion(-) > > > > This commit seems to cause a crash in a virtual drm gpu driver for > > Android. I have reverted this, and the next commit in the series from > > Linus's tree and all is good again. > > > > Any ideas? > > Well no, but also this patch looks very questionable of hand-rolling > drm_poll. Yes you can do driver private events like > DRM_VMW_EVENT_FENCE_SIGNALED, that's fine. But you really should not need > to hand-roll the poll callback. vmwgfx (which generally is a very old > driver which has lots of custom stuff, so not a great example) doesn't do > that either. > > So that part should go no matter what I think. > -Daniel > -- > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch
