On 8/20/26 11:53 AM, Maxime Ripard wrote: > On Fri, Jul 31, 2026 at 07:19:29PM +0300, Cristian Ciocaltea wrote: >> drm_atomic_helper_connector_hdmi_hotplug() does not currently >> synchronize SCDC status on hotplug events, leaving the scrambler state >> potentially inconsistent after (re)connect. >> >> Hook drm_connector_hdmi_sync_scdc() into both the connect and disconnect >> paths, replacing the existing TODOs around missing scrambler handling. >> >> Tested-by: Maud Spierings <[email protected]> >> Tested-by: Diederik de Haas <[email protected]> # NanoPC-T6 LTS, Rock >> 5B >> Signed-off-by: Cristian Ciocaltea <[email protected]> >> --- >> drivers/gpu/drm/display/drm_hdmi_state_helper.c | 23 ++++++++++++++--------- >> 1 file changed, 14 insertions(+), 9 deletions(-) >> >> diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c >> b/drivers/gpu/drm/display/drm_hdmi_state_helper.c >> index 4a93c279c9a7..3377ea936120 100644 >> --- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c >> +++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c >> @@ -1205,13 +1205,16 @@ drm_atomic_helper_connector_hdmi_update(struct >> drm_connector *connector, >> enum drm_connector_status status) >> { >> const struct drm_edid *drm_edid; >> + int ret = 0; >> >> if (status == connector_status_disconnected) { >> - // TODO: also handle scramber, HDMI sink disconnected. >> - drm_connector_hdmi_audio_plugged_notify(connector, false); >> - drm_edid_connector_update(connector, NULL); >> - drm_connector_cec_phys_addr_invalidate(connector); >> - return 0; >> + ret = drm_connector_hdmi_sync_scdc(connector, false, ctx); >> + if (ret != -EDEADLK) { >> + drm_connector_hdmi_audio_plugged_notify(connector, >> false); >> + drm_edid_connector_update(connector, NULL); >> + drm_connector_cec_phys_addr_invalidate(connector); >> + } > > If there's a deadlock, shouldn't we restart the whole sequence there?
In that case we do already propagate -EDEADLK and let the callers (drm_helper_probe_detect_ctx(), drm_helper_probe_single_connector_modes()) to ensure the sequence is restarted. > Ie, we should return ret all the time anyway? And if we do that, we > should return ret for drm_edid_connector_update() too. Per .detect_ctx() contract, implementations shall return a drm_connector_status value or -EDEADLK only. On the other hand, .force_ctx() accepts any error code, but the probe helpers just log it. Hence returning anything else wouldn't really have an impact on the functionality. Returning errors from drm_edid_connector_update() would potentially override non-deadlock ones from sync_scdc(). Since both helpers already log their own failures, I think it isn't worth the trouble. > Either way, a comment on why we're doing it this way would be nice. Indeed. Would the following be too verbose? /* * The SCDC resync may reset the CRTC, which might involve aquiring * modeset locks. If that fails, -EDEADLK is reported and the callers * passing a non-NULL @ctx drop the locks and restart the sequence * - see drm_helper_probe_detect_ctx() and * drm_helper_probe_single_connector_modes(). * * The resync runs first, and the audio and CEC helpers only once the * link state has settled: the CRTC reset is a blocking commit, so on * success the pipeline is already up again, while on -EDEADLK nothing * has been resynced yet and the pending retry redoes everything. This * keeps userspace from acting upon a link that is about to be reset. * * -EDEADLK is the only status gating the helpers below, as it is the * sole one guaranteeing a new run. The other failures are merely * reported: .force_ctx() accepts any error code and the probe helpers * just log it, while .detect_ctx() has to swallow it, being only * allowed to return a drm_connector_status value or -EDEADLK. * Propagating the status of drm_edid_connector_update() on top would * therefore only make it compete with an earlier resync failure over a * value that triggers no recovery, the more so as both helpers already * log their own errors. */ Thanks, Cristian
