[PATCH 2/4] drm/i915/vlv: Reset the ADPA in vlv_display_power_well_init()

From: Lyude
Date: Mon Aug 22 2016 - 11:32:12 EST


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()

Cc: stable@xxxxxxxxxxxxxxx
Acked-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Lyude <cpaul@xxxxxxxxxx>
Reviewed-by: Ville SyrjÃlà <ville.syrjala@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/intel_crt.c | 2 +-
drivers/gpu/drm/i915/intel_drv.h | 2 +-
drivers/gpu/drm/i915/intel_runtime_pm.c | 7 +++++++
3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
index e4dc33e..d0fb961 100644
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -713,7 +713,7 @@ 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 = dev->dev_private;
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index f7f0f01..14d1dc6 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1052,7 +1052,7 @@ 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,
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index 7fb1da4..4a3fd3a 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -952,6 +952,7 @@ 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;

/*
@@ -987,6 +988,12 @@ 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->dev, encoder) {
+ if (encoder->type == INTEL_OUTPUT_ANALOG)
+ intel_crt_reset(&encoder->base);
+ }
+
i915_redisable_vga_power_on(dev_priv->dev);
}

--
2.7.4