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 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 at vger.kernel.org
Signed-off-by: Lyude <cpaul at redhat.com>
---
drivers/gpu/drm/i915/intel_runtime_pm.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c
b/drivers/gpu/drm/i915/intel_runtime_pm.c
index 80e8bd4..c7d195f 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 drm_encoder *encoder, *vga_encoder = NULL;
enum pipe pipe;
/*
@@ -935,6 +936,17 @@ 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 */
+ drm_for_each_encoder(encoder, dev_priv->dev) {
+ if (encoder->encoder_type == DRM_MODE_ENCODER_DAC) {
+ vga_encoder = encoder;
+ break;
+ }
+ }
+
+ if (vga_encoder && vga_encoder->funcs->reset)
+ vga_encoder->funcs->reset(vga_encoder);
+
i915_redisable_vga_power_on(dev_priv->dev);
}
--
2.5.5
