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Imre Deak authored
The issue fixed in commit a8ddac7c ("drm/i915: Avoid HPD poll detect triggering a new detect cycle") on VLV, CHV is still present on platforms where the display hotplug detection functionality is available whenever the device is in D0 state (hence these platforms switch to HPD polling only when the device is runtime suspended). The above commit avoids an endless i915_hpd_poll_init_work() -> connector detect loop by making sure that by the end of i915_hpd_poll_init_work() all display power references acquired by the connector detect functions which can trigger a new cycle (display core power domain) are dropped. However on platforms where HPD polling is enabled/disabled only from the runtime suspend/resume handlers, this is not ensured: for instance eDP VDD, TypeC port PHYs and the runtime autosuspend delay may still keep the device runtime resumed (via a power reference acquired during connector detection and hence result in an endless loop like the above). Solve the problem described in the above commit on all platforms, by making sure that a i915_hpd_poll_init_work() -> connector detect sequence can't take any power reference in the first place which would trigger a new cycle, instead of relying on these power references to be dropped by the end of the sequence. With the default runtime autosuspend delay (10 sec) this issue didn't happen in practice, since the device remained runtime resumed for the whole duration of the above sequence. CI/IGT tests however set the autosuspend delay to 0, which makes the problem visible, see References: below. Tested on GLK, CHV. v2: Don't warn about a requeued work, to account for disabling polling directly during driver loading, reset and system resume. References: https://gitlab.freedesktop.org/drm/intel/-/issues/7940#note_1997403Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Jouni Högander <jouni.hogander@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20230809104307.1218058-1-imre.deak@intel.com
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