[PATCH 14/15] drm/i915/mst: use reference counted connectors.
Daniel Vetter
daniel at ffwll.ch
Fri Apr 22 09:03:19 UTC 2016
On Fri, Apr 15, 2016 at 03:10:45PM +1000, Dave Airlie wrote:
> From: Dave Airlie <airlied at redhat.com>
>
> Don't just free the connector when we get the destroy callback.
>
> Drop a reference to it, and set it's mst_port to NULL so
> no more mst work is done on it.
>
> Signed-off-by: Dave Airlie <airlied at redhat.com>
Looks correct, but two comments for better api for shared helpers inline below.
-Daniel
> ---
> drivers/gpu/drm/i915/intel_dp_mst.c | 46 ++++++++++++++++++-------------------
> drivers/gpu/drm/i915/intel_drv.h | 2 +-
> 2 files changed, 24 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
> index a2bd698..2e730b6 100644
> --- a/drivers/gpu/drm/i915/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/intel_dp_mst.c
> @@ -113,7 +113,7 @@ static void intel_mst_disable_dp(struct intel_encoder *encoder)
>
> DRM_DEBUG_KMS("%d\n", intel_dp->active_mst_links);
>
> - drm_dp_mst_reset_vcpi_slots(&intel_dp->mst_mgr, intel_mst->port);
> + drm_dp_mst_reset_vcpi_slots(&intel_dp->mst_mgr, intel_mst->connector->port);
>
> ret = drm_dp_update_payload_part1(&intel_dp->mst_mgr);
> if (ret) {
> @@ -138,10 +138,12 @@ static void intel_mst_post_disable_dp(struct intel_encoder *encoder)
> /* and this can also fail */
> drm_dp_update_payload_part2(&intel_dp->mst_mgr);
>
> - drm_dp_mst_deallocate_vcpi(&intel_dp->mst_mgr, intel_mst->port);
> + drm_dp_mst_deallocate_vcpi(&intel_dp->mst_mgr, intel_mst->connector->port);
>
> intel_dp->active_mst_links--;
> - intel_mst->port = NULL;
> +
> + drm_connector_unreference(&intel_mst->connector->base);
> + intel_mst->connector = NULL;
> if (intel_dp->active_mst_links == 0) {
> intel_dig_port->base.post_disable(&intel_dig_port->base);
> intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_OFF);
> @@ -181,7 +183,9 @@ static void intel_mst_pre_enable_dp(struct intel_encoder *encoder)
> found->encoder = encoder;
>
> DRM_DEBUG_KMS("%d\n", intel_dp->active_mst_links);
> - intel_mst->port = found->port;
> +
> + intel_mst->connector = found;
> + drm_connector_reference(&intel_mst->connector->base);
>
> if (intel_dp->active_mst_links == 0) {
> intel_prepare_ddi_buffer(&intel_dig_port->base);
> @@ -199,7 +203,7 @@ static void intel_mst_pre_enable_dp(struct intel_encoder *encoder)
> }
>
> ret = drm_dp_mst_allocate_vcpi(&intel_dp->mst_mgr,
> - intel_mst->port,
> + intel_mst->connector->port,
> intel_crtc->config->pbn, &slots);
> if (ret == false) {
> DRM_ERROR("failed to allocate vcpi\n");
> @@ -248,7 +252,7 @@ static bool intel_dp_mst_enc_get_hw_state(struct intel_encoder *encoder,
> {
> struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
> *pipe = intel_mst->pipe;
> - if (intel_mst->port)
> + if (intel_mst->connector)
> return true;
> return false;
> }
> @@ -312,6 +316,11 @@ static int intel_dp_mst_get_ddc_modes(struct drm_connector *connector)
> struct edid *edid;
> int ret;
>
> + if (!intel_connector->port || !intel_dp) {
> + ret = intel_connector_update_modes(connector, NULL);
> + return ret;
> + }
> +
> edid = drm_dp_mst_get_edid(connector, &intel_dp->mst_mgr, intel_connector->port);
> if (!edid)
> return 0;
> @@ -328,6 +337,8 @@ intel_dp_mst_detect(struct drm_connector *connector, bool force)
> struct intel_connector *intel_connector = to_intel_connector(connector);
> struct intel_dp *intel_dp = intel_connector->mst_port;
>
> + if (!intel_connector->port || !intel_dp)
> + return connector_status_disconnected;
> return drm_dp_mst_detect_port(connector, &intel_dp->mst_mgr, intel_connector->port);
Should we push this change and the preceeding one into dp helpers, i.e.
make them cope with a null port? Otoh more work to fish out the
->mst_mgr, so not sure.
Hm ... isn't the mst_mgr a redundant argument, and we could figure that
out purely from the port? Would be a bit of refactoring, but I think the
shared code for this crucial bit of semantics (there's no way the mst port
is ever connected if it's unplugged) would be good.
> }
>
> @@ -393,6 +404,8 @@ static struct drm_encoder *intel_mst_atomic_best_encoder(struct drm_connector *c
> struct intel_dp *intel_dp = intel_connector->mst_port;
> struct intel_crtc *crtc = to_intel_crtc(state->crtc);
>
> + if (!intel_dp)
> + return NULL;
> return &intel_dp->mst_encoders[crtc->pipe]->base.base;
> }
>
> @@ -400,6 +413,8 @@ static struct drm_encoder *intel_mst_best_encoder(struct drm_connector *connecto
> {
> struct intel_connector *intel_connector = to_intel_connector(connector);
> struct intel_dp *intel_dp = intel_connector->mst_port;
> + if (!intel_dp)
> + return NULL;
> return &intel_dp->mst_encoders[0]->base.base;
> }
>
> @@ -506,29 +521,14 @@ static void intel_dp_destroy_mst_connector(struct drm_dp_mst_topology_mgr *mgr,
> struct intel_connector *intel_connector = to_intel_connector(connector);
> struct drm_device *dev = connector->dev;
>
> - /* need to nuke the connector */
> - drm_modeset_lock_all(dev);
> - if (connector->state->crtc) {
> - struct drm_mode_set set;
> - int ret;
> -
> - memset(&set, 0, sizeof(set));
> - set.crtc = connector->state->crtc,
> -
> - ret = drm_atomic_helper_set_config(&set);
> -
> - WARN(ret, "Disabling mst crtc failed with %i\n", ret);
> - }
> - drm_modeset_unlock_all(dev);
> -
> intel_connector->unregister(intel_connector);
>
> drm_modeset_lock_all(dev);
> intel_connector_remove_from_fbdev(intel_connector);
> - drm_connector_cleanup(connector);
> + intel_connector->mst_port = NULL;
> drm_modeset_unlock_all(dev);
Hm, ugly that we still need to grab modeset locks here. I'd like to avoid
that, since it could be a major stall. Maybe we need to have a separate
lock for the fbdev connector list, and then push the locking for that
(including refcounting) down into fbdev helpers?
>
> - kfree(intel_connector);
> + drm_connector_unreference(&intel_connector->base);
> DRM_DEBUG_KMS("\n");
> }
>
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 4c027d6..0d2360e 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -831,7 +831,7 @@ struct intel_dp_mst_encoder {
> struct intel_encoder base;
> enum pipe pipe;
> struct intel_digital_port *primary;
> - void *port; /* store this opaque as its illegal to dereference it */
> + struct intel_connector *connector;
> };
>
> static inline enum dpio_channel
> --
> 2.5.5
>
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--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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