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
