On Thu, 2018-11-29 at 07:37 +0000, Lisovskiy, Stanislav wrote:
On Wed, 2018-11-28 at 22:21 +0100, Daniel Vetter wrote:
I tried to read the bug and I have no idea what's going on here. Userspace is supposed to shut off outputs that are disconnected, whether that's DP, DP MST or something else shouldn't matter. New connectors can come&go as they see fit. Also not really something special.
Why do we need to dynamically hide an output here? Note that this also affects normal DP ports, which I have no idea is actually what you want to do or not.
This bug is real and easily reproducible with recent drm-tip. Unplugging and then quickly plugging back periodically leaves both my external displays connected to the docking station blank, there are also many duplicate bugs for this, which I simply didn't track. This patch at least fixes that annoying thing. The userspace seems to get confused when we are returning two different connector ids, one in disconnected state and another in connected state for the same output. This results in userspace believing that nothing had changed and drm_mode_setcrtc call is not required( I have done traces confirming that theory).
This could be also fixed in userspace by checking connectors more carefully - that fix I've also implemented for Intel DDX and attached to the bug, however seems that this happens also for Wayland.
In addition to what I said above, I checked your changes instead of proposed(also with locking) - it doesn't help, the displays get blank after unplug/plug.
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c index 4de247ddf05f..e1b66396c83b 100644 --- a/drivers/gpu/drm/i915/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/intel_dp_mst.c @@ -499,6 +499,8 @@ static void intel_dp_register_mst_connector(struct drm_connector *connector) drm_fb_helper_add_one_connector(&dev_priv->fbdev-
helper,
connector);
- list_move(&connector->head, &connector->dev-
mode_config.connector_list);
- drm_connector_register(connector);
}
-- Best Regards,
Lisovskiy Stanislav _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel