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authorLyude Paul <lyude@redhat.com>2018-10-16 23:39:46 +0300
committerLyude Paul <lyude@redhat.com>2018-10-17 20:50:14 +0300
commit39b50c603878f4f8ae541ac4088a805d588abc79 (patch)
tree894400108b7b0e6a7cdbcb0cb81cabfe9a6fe0cf /drivers/gpu/drm/drm_atomic_uapi.c
parent20fd600099754bb1d29405247c6c2b74ebc3b9f2 (diff)
downloadlinux-39b50c603878f4f8ae541ac4088a805d588abc79.tar.xz
drm/atomic_helper: Stop modesets on unregistered connectors harder
Unfortunately, it appears our fix in: commit b5d29843d8ef ("drm/atomic_helper: Allow DPMS On<->Off changes for unregistered connectors") Which attempted to work around the problems introduced by: commit 4d80273976bf ("drm/atomic_helper: Disallow new modesets on unregistered connectors") Is still not the right solution, as modesets can still be triggered outside of drm_atomic_set_crtc_for_connector(). So in order to fix this, while still being careful that we don't break modesets that a driver may perform before being registered with userspace, we replace connector->registered with a tristate member, connector->registration_state. This allows us to keep track of whether or not a connector is still initializing and hasn't been exposed to userspace, is currently registered and exposed to userspace, or has been legitimately removed from the system after having once been present. Using this info, we can prevent userspace from performing new modesets on unregistered connectors while still allowing the driver to perform modesets on unregistered connectors before the driver has finished being registered. Changes since v1: - Fix WARN_ON() in drm_connector_cleanup() that CI caught with this patchset in igt@drv_module_reload@basic-reload-inject and igt@drv_module_reload@basic-reload by checking if the connector is registered instead of unregistered, as calling drm_connector_cleanup() on a connector that hasn't been registered with userspace yet should stay valid. - Remove unregistered_connector_check(), and just go back to what we were doing before in commit 4d80273976bf ("drm/atomic_helper: Disallow new modesets on unregistered connectors") except replacing READ_ONCE(connector->registered) with drm_connector_is_unregistered(). This gets rid of the behavior of allowing DPMS On<->Off, but that should be fine as it's more consistent with the UAPI we had before - danvet - s/drm_connector_unregistered/drm_connector_is_unregistered/ - danvet - Update documentation, fix some typos. Fixes: b5d29843d8ef ("drm/atomic_helper: Allow DPMS On<->Off changes for unregistered connectors") Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: stable@vger.kernel.org Cc: David Airlie <airlied@linux.ie> Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20181016203946.9601-1-lyude@redhat.com
Diffstat (limited to 'drivers/gpu/drm/drm_atomic_uapi.c')
-rw-r--r--drivers/gpu/drm/drm_atomic_uapi.c21
1 files changed, 0 insertions, 21 deletions
diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index a22d6f269b07..d5b7f315098c 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -299,27 +299,6 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
struct drm_connector *connector = conn_state->connector;
struct drm_crtc_state *crtc_state;
- /*
- * For compatibility with legacy users, we want to make sure that
- * we allow DPMS On<->Off modesets on unregistered connectors, since
- * legacy modesetting users will not be expecting these to fail. We do
- * not however, want to allow legacy users to assign a connector
- * that's been unregistered from sysfs to another CRTC, since doing
- * this with a now non-existent connector could potentially leave us
- * in an invalid state.
- *
- * Since the connector can be unregistered at any point during an
- * atomic check or commit, this is racy. But that's OK: all we care
- * about is ensuring that userspace can't use this connector for new
- * configurations after it's been notified that the connector is no
- * longer present.
- */
- if (!READ_ONCE(connector->registered) && crtc) {
- DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] is not registered\n",
- connector->base.id, connector->name);
- return -EINVAL;
- }
-
if (conn_state->crtc == crtc)
return 0;