[Intel-gfx] [PATCH 2/6] drm/atomic: Only destroy connector states with connection mutex held

[Rob Clark]

On Wed, Nov 19, 2014 at 12:38 PM, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> Otherwise the connector might have been unplugged and destroyed while
> we didn't look. Yet another fallout from DP MST hotplugging that I
> didn't consider.
>
> To make sure we get this right add an appropriate WARN_ON to
> drm_atomic_state_clear (obviously only when we actually have a state
> to clear up). And reorder all the state_clear and backoff calls to
> make it work out properly.
>
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>

Reviewed-by: Rob Clark <robdclark at gmail.com>

> ---
>  drivers/gpu/drm/drm_atomic.c        |  9 ++++++---
>  drivers/gpu/drm/drm_atomic_helper.c | 14 +++++++-------
>  2 files changed, 13 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index 90b2d1644bd7..67c1dc894bd9 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -112,21 +112,24 @@ EXPORT_SYMBOL(drm_atomic_state_alloc);
>  void drm_atomic_state_clear(struct drm_atomic_state *state)
>  {
>         struct drm_device *dev = state->dev;
> +       struct drm_mode_config *config = &dev->mode_config;
>         int i;
>
>         DRM_DEBUG_KMS("Clearing atomic state %p\n", state);
>
> -       for (i = 0; i < dev->mode_config.num_connector; i++) {
> +       for (i = 0; i < config->num_connector; i++) {
>                 struct drm_connector *connector = state->connectors[i];
>
>                 if (!connector)
>                         continue;
>
> +               WARN_ON(!drm_modeset_is_locked(&config->connection_mutex));
> +
>                 connector->funcs->atomic_destroy_state(connector,
>                                                        state->connector_states[i]);
>         }
>
> -       for (i = 0; i < dev->mode_config.num_crtc; i++) {
> +       for (i = 0; i < config->num_crtc; i++) {
>                 struct drm_crtc *crtc = state->crtcs[i];
>
>                 if (!crtc)
> @@ -136,7 +139,7 @@ void drm_atomic_state_clear(struct drm_atomic_state *state)
>                                                   state->crtc_states[i]);
>         }
>
> -       for (i = 0; i < dev->mode_config.num_total_plane; i++) {
> +       for (i = 0; i < config->num_total_plane; i++) {
>                 struct drm_plane *plane = state->planes[i];
>
>                 if (!plane)
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> index fad2b932cf72..0cd054615920 100644
> --- a/drivers/gpu/drm/drm_atomic_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_helper.c
> @@ -1217,8 +1217,8 @@ fail:
>
>         return ret;
>  backoff:
> -       drm_atomic_legacy_backoff(state);
>         drm_atomic_state_clear(state);
> +       drm_atomic_legacy_backoff(state);
>
>         /*
>          * Someone might have exchanged the framebuffer while we dropped locks
> @@ -1285,8 +1285,8 @@ fail:
>
>         return ret;
>  backoff:
> -       drm_atomic_legacy_backoff(state);
>         drm_atomic_state_clear(state);
> +       drm_atomic_legacy_backoff(state);
>
>         /*
>          * Someone might have exchanged the framebuffer while we dropped locks
> @@ -1462,8 +1462,8 @@ fail:
>
>         return ret;
>  backoff:
> -       drm_atomic_legacy_backoff(state);
>         drm_atomic_state_clear(state);
> +       drm_atomic_legacy_backoff(state);
>
>         /*
>          * Someone might have exchanged the framebuffer while we dropped locks
> @@ -1528,8 +1528,8 @@ fail:
>
>         return ret;
>  backoff:
> -       drm_atomic_legacy_backoff(state);
>         drm_atomic_state_clear(state);
> +       drm_atomic_legacy_backoff(state);
>
>         goto retry;
>  }
> @@ -1587,8 +1587,8 @@ fail:
>
>         return ret;
>  backoff:
> -       drm_atomic_legacy_backoff(state);
>         drm_atomic_state_clear(state);
> +       drm_atomic_legacy_backoff(state);
>
>         goto retry;
>  }
> @@ -1646,8 +1646,8 @@ fail:
>
>         return ret;
>  backoff:
> -       drm_atomic_legacy_backoff(state);
>         drm_atomic_state_clear(state);
> +       drm_atomic_legacy_backoff(state);
>
>         goto retry;
>  }
> @@ -1725,8 +1725,8 @@ fail:
>
>         return ret;
>  backoff:
> -       drm_atomic_legacy_backoff(state);
>         drm_atomic_state_clear(state);
> +       drm_atomic_legacy_backoff(state);
>
>         /*
>          * Someone might have exchanged the framebuffer while we dropped locks
> --
> 2.1.1
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx