2016-04-19 20:40:59

by Lyude Paul

[permalink] [raw]
Subject: [PATCH v4 2/3] drm/i915/vlv: Reset the ADPA in vlv_display_power_well_init()

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: [email protected]
Signed-off-by: Lyude <[email protected]>
Reviewed-by: Ville Syrjälä <[email protected]>
---
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 220ca91..54db931 100644
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -707,7 +707,7 @@ 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 e0fcfa1..4e96d5c 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1044,7 +1044,7 @@ 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 80e8bd4..b643533 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -902,6 +902,7 @@ static bool vlv_power_well_enabled(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;

/*
@@ -935,6 +936,12 @@ 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);
}

--
2.5.5