On Fri, Mar 04, 2016 at 03:43:53PM -0800, Douglas Anderson wrote:
> On a system I'm doing development on I found a crash. The crawl looked
> like:
>
> PC is at drm_atomic_add_affected_connectors+0x98/0xe8
> ...
> drm_atomic_add_affected_connectors from __drm_atomic_helper_set_config+0x218/0x344
> __drm_atomic_helper_set_config from restore_fbdev_mode+0x108/0x250
> restore_fbdev_mode from drm_fb_helper_restore_fbdev_mode_unlocked+0x3c/0x80
> drm_fb_helper_restore_fbdev_mode_unlocked from rockchip_drm_lastclose+0x1c/0x20
> rockchip_drm_lastclose from drm_lastclose+0x4c/0x104
> drm_lastclose from drm_release+0x424/0x47c
> drm_release from __fput+0xf8/0x1d4
> __fput from ____fput+0x18/0x1c
> ____fput from task_work_run+0xa8/0xbc
> task_work_run from do_exit+0x448/0x91c
> do_exit from do_group_exit+0x5c/0xcc
> do_group_exit from get_signal+0x4dc/0x57c
> get_signal from do_signal+0x9c/0x3b4
> do_signal from do_work_pending+0x60/0xb8
> do_work_pending from slow_work_pending+0xc/0x20
>
> I found that I could fix the crash by checking connector->state against
> NULL. This isn't code I'm familiar with and I didn't dig too deep, so
> I'd appreciate any opinions about whether this is a sane thing to do.
> Note that I don't actually have graphics up on my system at the moment,
> so perhaps this is all just a symptom of the strange state I'm in.
>
> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
This is a driver bug - under atomic the assumption is that there is
_always_ a current software state. Most driver set up the initial
"everything off" state in the ->reset functions.
-Daniel
> ---
> drivers/gpu/drm/drm_atomic.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index 8fb469c4e4b8..3377d7ddc6d1 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -1147,7 +1147,7 @@ drm_atomic_add_affected_connectors(struct drm_atomic_state *state,
> * current configuration.
> */
> drm_for_each_connector(connector, state->dev) {
> - if (connector->state->crtc != crtc)
> + if (!connector->state || connector->state->crtc != crtc)
> continue;
>
> conn_state = drm_atomic_get_connector_state(state, connector);
> --
> 2.7.0.rc3.207.g0ac5344
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel
