[PATCH 3.4 020/176] drm/i915: Unlock panel even when LVDS is disabled

[lizf]

From: Daniel Vetter <daniel.vetter@xxxxxxxx>

3.4.107-rc1 review patch.  If anyone has any objections, please let me know.

------------------


commit b0616c5306b342ceca07044dbc4f917d95c4f825 upstream.

Otherwise we'll have backtraces in assert_panel_unlocked because the
BIOS locks the register. In the reporter's case this regression was
introduced in

commit c31407a3672aaebb4acddf90944a114fa5c8af7b
Author: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Date:   Thu Oct 18 21:07:01 2012 +0100

    drm/i915: Add no-lvds quirk for Supermicro X7SPA-H

Reported-by: Alexey Orishko <alexey.orishko@xxxxxxxxx>
Cc: Alexey Orishko <alexey.orishko@xxxxxxxxx>
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Francois Tigeot <ftigeot@xxxxxxxxxxxx>
Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx>
Tested-by: Alexey Orishko <alexey.orishko@xxxxxxxxx>
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@xxxxxxxxxx>
---
 drivers/gpu/drm/i915/intel_lvds.c | 24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index 77190cc..3febe29 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -932,6 +932,17 @@ bool intel_lvds_init(struct drm_device *dev)
 	int pipe;
 	u8 pin;
 
+	/*
+	 * Unlock registers and just leave them unlocked. Do this before
+	 * checking quirk lists to avoid bogus WARNINGs.
+	 */
+	if (HAS_PCH_SPLIT(dev)) {
+		I915_WRITE(PCH_PP_CONTROL,
+			   I915_READ(PCH_PP_CONTROL) | PANEL_UNLOCK_REGS);
+	} else {
+		I915_WRITE(PP_CONTROL,
+			   I915_READ(PP_CONTROL) | PANEL_UNLOCK_REGS);
+	}
 	if (!intel_lvds_supported(dev))
 		return false;
 
@@ -1109,19 +1120,6 @@ out:
 		pwm = I915_READ(BLC_PWM_PCH_CTL1);
 		pwm |= PWM_PCH_ENABLE;
 		I915_WRITE(BLC_PWM_PCH_CTL1, pwm);
-		/*
-		 * Unlock registers and just
-		 * leave them unlocked
-		 */
-		I915_WRITE(PCH_PP_CONTROL,
-			   I915_READ(PCH_PP_CONTROL) | PANEL_UNLOCK_REGS);
-	} else {
-		/*
-		 * Unlock registers and just
-		 * leave them unlocked
-		 */
-		I915_WRITE(PP_CONTROL,
-			   I915_READ(PP_CONTROL) | PANEL_UNLOCK_REGS);
 	}
 	dev_priv->lid_notifier.notifier_call = intel_lid_notify;
 	if (acpi_lid_notifier_register(&dev_priv->lid_notifier)) {
-- 
1.9.1

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