This fixes reprobing of display connectors on resume. After some talking with danvet on IRC, I learned that calling drm_helper_hpd_irq_event() does actually trigger a full reprobe of each connector's status. It turns out this is the actual reason reprobing on resume hasn't been working (this was observed on a T440s):
- We call hpd_init() - We check each connector for a couple of things before marking connector->polled with DRM_CONNECTOR_POLL_HPD, one of which is an active encoder. Of course, a disconnected port won't have an active encoder, so we don't add the flag to any of the connectors. - We call drm_helper_hpd_irq_event() - drm_helper_irq_event() checks each connector for the DRM_CONNECTOR_POLL_HPD flag. The only one that has it is eDP-1, so we skip reprobing each connector except that one.
In addition, we also now avoid setting connector->polled to DRM_CONNECTOR_POLL_HPD for MST connectors, since their reprobing is handled by the mst helpers. This is probably what was originally intended to happen here.
Changes since V1: * Use the explanation of the issue as the commit message instead * Change the title of the commit, since this does more then just stop a check for an encoder now * Add "Fixes" line for the patch that introduced this regression * Don't enable DRM_CONNECTOR_POLL_HPD for mst connectors
Changes since V2: * Put patch changelog above Signed-off-by * Follow Daniel Vetter's suggestion for making the code here a bit more legible
Fixes: 0e32b39ceed6 ("drm/i915: add DP 1.2 MST support (v0.7)") Cc: stable@vger.kernel.org Signed-off-by: Lyude cpaul@redhat.com --- drivers/gpu/drm/i915/intel_hotplug.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c index b177857..d7a6437 100644 --- a/drivers/gpu/drm/i915/intel_hotplug.c +++ b/drivers/gpu/drm/i915/intel_hotplug.c @@ -468,9 +468,14 @@ void intel_hpd_init(struct drm_i915_private *dev_priv) list_for_each_entry(connector, &mode_config->connector_list, head) { struct intel_connector *intel_connector = to_intel_connector(connector); connector->polled = intel_connector->polled; - if (connector->encoder && !connector->polled && I915_HAS_HOTPLUG(dev) && intel_connector->encoder->hpd_pin > HPD_NONE) - connector->polled = DRM_CONNECTOR_POLL_HPD; + + /* MST has a dynamic intel_connector->encoder and it's reprobing + * is all handled by the MST helpers. */ if (intel_connector->mst_port) + continue; + + if (!connector->polled && I915_HAS_HOTPLUG(dev) && + intel_connector->encoder->hpd_pin > HPD_NONE) connector->polled = DRM_CONNECTOR_POLL_HPD; }