Quoting Kuogee Hsieh (2022-04-25 22:56:35)
Current DP driver implementation has adding safe mode done at dp_hpd_plug_handle() which is expected to be executed under event thread context.
However there is possible circular locking happen (see blow stack trace) after edp driver call dp_hpd_plug_handle() from dp_bridge_enable() which is executed under drm_thread context.
After review all possibilities methods and as discussed on https://patchwork.freedesktop.org/patch/483155/, supporting EDID compliance tests in the driver is quite hacky. As seen with other vendor drivers, supporting these will be much easier with IGT. Hence removing all the related fail safe code for it so that no possibility of circular lock will happen.
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Changes in v2: -- re text commit title -- remove all fail safe mode
Signed-off-by: Kuogee Hsieh quic_khsieh@quicinc.com
Should add some Fixes tags here, probably for the first introduction of this logic and the one that moved stuff around to try to avoid the lockdep warning.