[Intel-gfx] [PATCH] drm/i915: Check and update LVDS connector status after receiving LID notification event

[yakui.zhao at intel.com]

From: Zhao Yakui <yakui.zhao at intel.com>

Now the LID state is used to check whether the LVDS is connected or
disconnected. And when the LID is closed, it means that the LVDS is
disconnected. When it is reopened, it means that the LVDS is connected.

At the same time on some distributions the LID event is also used to put
the system into suspend state. When the LID is closed, the system will enter
the suspend state. When the LID is reopened, the system will be resumed.

In such case when the LID is closed, the LVDS is detected as disconnected and
then the system will enter the suspended state. When the LID is reopened, the
system will be resumed. But as the LVDS status is not updated in course of
resume, it will cause that the LVDS connector is marked as unused and
disabled. Even when we try to configure the display mode for LVDS, it still
can't work if we don't update the status of LVDS connector.

check and update the status of LVDS connector after receiving the LID
notication event. Then after the system is resumed from suspended state, we
can set the display mode for LVDS correctly.

Signed-off-by: Zhao Yakui <yakui.zhao at intel.com>
Reported-by:  Dirk Hohndel <hohndel at infradead.org>
---
 drivers/gpu/drm/i915/i915_drv.h   |    1 +
 drivers/gpu/drm/i915/intel_lvds.c |    9 +++++++++
 2 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index ca1ba42..cb97851 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -551,6 +551,7 @@ typedef struct drm_i915_private {
 	u16 orig_clock;
 	int child_dev_num;
 	struct child_device_config *child_dev;
+	struct drm_connector *int_lvds_connector;
 } drm_i915_private_t;
 
 /** driver private structure attached to each drm_gem_object */
diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index 02b813e..0eba2ea 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -679,7 +679,14 @@ static int intel_lid_notify(struct notifier_block *nb, unsigned long val,
 	struct drm_i915_private *dev_priv =
 		container_of(nb, struct drm_i915_private, lid_notifier);
 	struct drm_device *dev = dev_priv->dev;
+	struct drm_connector *connector = dev_priv->int_lvds_connector;
 
+	/*
+	 * check and update the status of LVDS connector after receiving
+	 * the LID nofication event.
+	 */
+	if (connector)
+		connector->status = connector->funcs->detect(connector);
 	if (!acpi_lid_open()) {
 		dev_priv->modeset_on_lid = 1;
 		return NOTIFY_OK;
@@ -1180,6 +1187,8 @@ out:
 		DRM_DEBUG_KMS("lid notifier registration failed\n");
 		dev_priv->lid_notifier.notifier_call = NULL;
 	}
+	/* keep the LVDS connector */
+	dev_priv->int_lvds_connector = connector;
 	drm_sysfs_connector_add(connector);
 	return;
 
-- 
1.5.4.5