drm/i915: resurrect panel lid handling

But disabled by default. This essentially reverts

commit bcd5023c961a44c7149936553b6929b2b233dd27
Author: Dave Airlie <airlied@redhat.com>
Date:   Mon Mar 14 14:17:55 2011 +1000

    drm/i915: disable opregion lid detection for now

but leaves the autodetect mode disabled. There's also the explicit lid
status option added in

commit fca874092597ef946b8f07031d8c31c58b212144
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Thu Feb 17 13:44:48 2011 +0000

    drm/i915: Add a module parameter to ignore lid status

Which overloaded the meaning for the panel_ignore_lid parameter even
more. To fix up this mess, give the non-negative numbers 0,1 the
original meaning back and use negative numbers to force a given state.
So now we have

1  - disable autodetect, return unknown
0  - enable autodetect
-1 - force to disconnected/lid closed
-2 - force to connected/lid open

v2: My C programmer license has been revoked ...

v3: Beautify the code a bit, as suggested by Chris Wilson.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=27622
Tested-by: Andreas Sturmlechner <andreas.sturmlechner@gmail.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

2 files changed, 14 insertions, 17 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index a3d754dba5a9..f5b505a5b81e 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -47,11 +47,11 @@ MODULE_PARM_DESC(modeset,
 unsigned int i915_fbpercrtc __always_unused = 0;
 module_param_named(fbpercrtc, i915_fbpercrtc, int, 0400);
 
-int i915_panel_ignore_lid __read_mostly = 0;
+int i915_panel_ignore_lid __read_mostly = 1;
 module_param_named(panel_ignore_lid, i915_panel_ignore_lid, int, 0600);
 MODULE_PARM_DESC(panel_ignore_lid,
-                "Override lid status (0=autodetect [default], 1=lid open, "
-                "-1=lid closed)");
+                "Override lid status (0=autodetect, 1=autodetect disabled [default], "
+                "-1=force lid closed, -2=force lid open)");
 
 unsigned int i915_powersave __read_mostly = 1;
 module_param_named(powersave, i915_powersave, int, 0600);
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index 41d463573baa..c758ad277473 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -275,7 +275,7 @@ static void intel_panel_actually_set_backlight(struct drm_device *dev, u32 level
         }
 
         tmp = I915_READ(BLC_PWM_CTL);
-        if (INTEL_INFO(dev)->gen < 4) 
+        if (INTEL_INFO(dev)->gen < 4)
                 level <<= 1;
         tmp &= ~BACKLIGHT_DUTY_CYCLE_MASK;
         I915_WRITE(BLC_PWM_CTL, tmp | level);
@@ -374,26 +374,23 @@ static void intel_panel_init_backlight(struct drm_device *dev)
 enum drm_connector_status
 intel_panel_detect(struct drm_device *dev)
 {
-#if 0
         struct drm_i915_private *dev_priv = dev->dev_private;
-#endif
-
-        if (i915_panel_ignore_lid)
-                return i915_panel_ignore_lid > 0 ?
-                        connector_status_connected :
-                        connector_status_disconnected;
 
-        /* opregion lid state on HP 2540p is wrong at boot up,
-         * appears to be either the BIOS or Linux ACPI fault */
-#if 0
         /* Assume that the BIOS does not lie through the OpRegion... */
-        if (dev_priv->opregion.lid_state)
+        if (!i915_panel_ignore_lid && dev_priv->opregion.lid_state) {
                 return ioread32(dev_priv->opregion.lid_state) & 0x1 ?
                         connector_status_connected :
                         connector_status_disconnected;
-#endif
+        }
 
-        return connector_status_unknown;
+        switch (i915_panel_ignore_lid) {
+        case -2:
+                return connector_status_connected;
+        case -1:
+                return connector_status_disconnected;
+        default:
+                return connector_status_unknown;
+        }
 }
 
 #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE