FAILED: patch "[PATCH] drm/i915/vlv: Reset the ADPA in vlv_display_power_well_init()" failed to apply to 4.7-stable tree

The patch below does not apply to the 4.7-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From: Lyude <[email protected]>
Date: Tue, 21 Jun 2016 17:03:42 -0400
Subject: [PATCH] drm/i915/vlv: Reset the ADPA in vlv_display_power_well_init()
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While VGA hotplugging worked(ish) before, it looks like that was mainly because we'd unintentionally enable it in valleyview_crt_detect_hotplug() when we did a force trigger. This doesn't work reliably enough because whenever the display powerwell on vlv gets disabled, the values set in VLV_ADPA get cleared and consequently VGA hotplugging gets disabled. This causes bugs such as one we found on an Intel NUC, where doing the following sequence of hotplugs:

- Disconnect all monitors
- Connect VGA
- Disconnect VGA
- Connect HDMI

Would result in VGA hotplugging becoming disabled, due to the powerwells getting toggled in the process of connecting HDMI.

Changes since v3:
- Expose intel_crt_reset() through intel_drv.h and call that in vlv_display_power_well_init() instead of encoder->base.funcs->reset(&encoder->base);

Changes since v2:
- Use intel_encoder structs instead of drm_encoder structs

Changes since v1:
- Instead of handling the register writes ourself, we just reuse intel_crt_detect()
- Instead of resetting the ADPA during display IRQ installation, we now reset them in vlv_display_power_well_init()

index 9cd88293c960..d172930ac1e7 100644
@@ -717,7 +717,7 @@ static int intel_crt_set_property(struct drm_connector *connector,
 	return 0;
 }
 
-static void intel_crt_reset(struct drm_encoder *encoder)
+void intel_crt_reset(struct drm_encoder *encoder)
 {
 	struct drm_device *dev = encoder->dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);

index 55aeaf041749..0aa1bedcf920 100644
@@ -1102,7 +1102,7 @@ void gen8_irq_power_well_pre_disable(struct drm_i915_private *dev_priv,
 
 /* intel_crt.c */
 void intel_crt_init(struct drm_device *dev);
-
+void intel_crt_reset(struct drm_encoder *encoder);
 
 /* intel_ddi.c */
 void intel_ddi_clk_select(struct intel_encoder *encoder,

index 6b78295f53db..b089ec89363d 100644
@@ -1078,6 +1078,7 @@ static void vlv_init_display_clock_gating(struct drm_i915_private *dev_priv)
 
 static void vlv_display_power_well_init(struct drm_i915_private *dev_priv)
 {
+	struct intel_encoder *encoder;
 	enum pipe pipe;
 
 	/*

@@ -1113,6 +1114,12 @@ static void vlv_display_power_well_init(struct drm_i915_private *dev_priv)
 
 	intel_hpd_init(dev_priv);
 
+	/* Re-enable the ADPA, if we have one */
+	for_each_intel_encoder(&dev_priv->drm, encoder) {
+		if (encoder->type == INTEL_OUTPUT_ANALOG)
+			intel_crt_reset(&encoder->base);
+	}
+
 	i915_redisable_vga_power_on(&dev_priv->drm);
 }