[PATCH] i915: slow acpi_lid_open() causes flickering

[Thomas Meyer]

acpi_lid_open() could take up to 10ms on my computer.
Some component is calling the drm GETCONNECTOR ioctl many times in a row.
This results in flickering (for example, when starting a video).
Fix it by assuming an always connected lid status.

This fixes bug http://bugzilla.kernel.org/show_bug.cgi?id=14670

---
 drivers/gpu/drm/i915/intel_lvds.c |   15 ++++++++++++++-
 1 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index aa74e59..0f0779c 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -632,6 +632,18 @@ static const struct dmi_system_id bad_lid_status[] = {
 	{ }
 };
 
+/* Some lid devices take a long time to report the lid status, assume they're connected*/
+static const struct dmi_system_id slow_lid_status[] = {
+	{
+		.ident = "Aspire 1810T",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 1810T"),
+		},
+	},
+	{ }
+};
+
 /**
  * Detect the LVDS connection.
  *
@@ -643,7 +655,8 @@ static enum drm_connector_status intel_lvds_detect(struct drm_connector *connect
 {
 	enum drm_connector_status status = connector_status_connected;
 
-	if (!acpi_lid_open() && !dmi_check_system(bad_lid_status))
+	if (!dmi_check_system(slow_lid_status) && !dmi_check_system(bad_lid_status))
+	    if (!acpi_lid_open())
 		status = connector_status_disconnected;
 
 	return status;
-- 
1.6.6


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