[ 3.5.y.z extended stable ] Patch "i915: ensure that VGA plane is disabled" has been added to staging queue

[Herton Ronaldo Krzesinski]

This is a note to let you know that I have just added a patch titled

    i915: ensure that VGA plane is disabled

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Herton

------

>From 9f7eacda1ad86023a173104f93ea5d8ac7af7bf0 Mon Sep 17 00:00:00 2001
From: Krzysztof Mazur <krzysiek at podlesie.net>
Date: Wed, 19 Dec 2012 11:03:41 +0100
Subject: [PATCH] i915: ensure that VGA plane is disabled

commit 0fde901f1ddd2ce0e380a6444f1fb7ca555859e9 upstream.

Some broken systems (like HP nc6120) in some cases, usually after LID
close/open, enable VGA plane, making display unusable (black screen on LVDS,
some strange mode on VGA output). We used to disable VGA plane only once at
startup. Now we also check, if VGA plane is still disabled while changing
mode, and fix that if something changed it.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=57434
Signed-off-by: Krzysztof Mazur <krzysiek at podlesie.net>
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
[bwh: Backported to 3.2: intel_modeset_setup_hw_state() does not
     exist, so call i915_redisable_vga() directly from intel_lid_notify()]
Signed-off-by: Ben Hutchings <ben at decadent.org.uk>
[ herton: use version for 3.2 which is also valid for 3.5, only had to
  adjust context ]
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 drivers/gpu/drm/i915/i915_drv.h      |    1 +
 drivers/gpu/drm/i915/intel_display.c |   17 +++++++++++++++++
 drivers/gpu/drm/i915/intel_lvds.c    |    1 +
 3 files changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b0b676a..a2c97bb 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1467,6 +1467,7 @@ static inline void intel_unregister_dsm_handler(void) { return; }

 /* modesetting */
 extern void intel_modeset_init_hw(struct drm_device *dev);
+extern void i915_redisable_vga(struct drm_device *dev);
 extern void intel_modeset_init(struct drm_device *dev);
 extern void intel_modeset_gem_init(struct drm_device *dev);
 extern void intel_modeset_cleanup(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 5cd6449..b61bc50 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6964,6 +6964,23 @@ void intel_modeset_init_hw(struct drm_device *dev)
 	}
 }

+void i915_redisable_vga(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	u32 vga_reg;
+
+	if (HAS_PCH_SPLIT(dev))
+		vga_reg = CPU_VGACNTRL;
+	else
+		vga_reg = VGACNTRL;
+
+	if (I915_READ(vga_reg) != VGA_DISP_DISABLE) {
+		DRM_DEBUG_KMS("Something enabled VGA plane, disabling it\n");
+		I915_WRITE(vga_reg, VGA_DISP_DISABLE);
+		POSTING_READ(vga_reg);
+	}
+}
+
 void intel_modeset_init(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index f85e2b1..37d7243 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -541,6 +541,7 @@ static int intel_lid_notify(struct notifier_block *nb, unsigned long val,

 	mutex_lock(&dev->mode_config.mutex);
 	drm_helper_resume_force_mode(dev);
+	i915_redisable_vga(dev);
 	mutex_unlock(&dev->mode_config.mutex);

 	return NOTIFY_OK;
--
1.7.9.5