On Mon, Nov 15, 2021 at 07:26:14PM +0000, Kasireddy, Vivek wrote: > 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 Yeah but that still leaves the problem of why exaxtly virtgpu is reinventing drm_poll here? Can you please replace it with drm_poll like all other drivers, including the ones that have private events? Thanks, Daniel > > 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 -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
