[PATCH 3.2 01/27] drm/i915: Unlock panel even when LVDS is disabled

From: Ben Hutchings
Date: Sun Dec 28 2014 - 20:18:11 EST


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

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

From: Daniel Vetter <daniel.vetter@xxxxxxxx>

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>
[bwh: Backported to 3.2: adjust context; comment was duplicated]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -914,6 +914,18 @@ bool intel_lvds_init(struct drm_device *
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);
+ }
+
/* Skip init on machines we know falsely report LVDS */
if (dmi_check_system(intel_no_lvds))
return false;
@@ -1088,19 +1100,6 @@ 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)) {

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