From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
The idea that ctg uses different HPD live state bits is
total nonsense, at least on my machine (Dell Latitude
E5400).
The only reason DP-B even works on my ctg is that DP-D
live state is stuck high, even though there is no physical
DP-D port. So when the detect checks DP-B live state it
sees the stuck live state of DP-D instead. If I hack
the driver to not register DP-D at all, and thus we never
enabe DP-D HPD, DP-B stops working as well.
Just to put some conclusive evidence into this mess,
here are the actual hotplug register values for each port:
Everything disconnected:
PORT_HOTPLUG_EN (0x00061110): 0x00000000
PORT_HOTPLUG_STAT (0x00061114): 0x00000000
PORT_HOTPLUG_EN (0x00061110): 0x08000000
PORT_HOTPLUG_STAT (0x00061114): 0x08000000
PORT_HOTPLUG_EN (0x00061110): 0x10000000
PORT_HOTPLUG_STAT (0x00061114): 0x00000000
PORT_HOTPLUG_EN (0x00061110): 0x20000000
PORT_HOTPLUG_STAT (0x00061114): 0x00000000
Only port B connected:
PORT_HOTPLUG_EN (0x00061110): 0x00000000
PORT_HOTPLUG_STAT (0x00061114): 0x00000000
PORT_HOTPLUG_EN (0x00061110): 0x08000000
PORT_HOTPLUG_STAT (0x00061114): 0x08000000
PORT_HOTPLUG_EN (0x00061110): 0x10000000
PORT_HOTPLUG_STAT (0x00061114): 0x00000000
PORT_HOTPLUG_EN (0x00061110): 0x20000000
PORT_HOTPLUG_STAT (0x00061114): 0x20000000
Only port C connected:
PORT_HOTPLUG_EN (0x00061110): 0x00000000
PORT_HOTPLUG_STAT (0x00061114): 0x00000000
PORT_HOTPLUG_EN (0x00061110): 0x08000000
PORT_HOTPLUG_STAT (0x00061114): 0x08000000
PORT_HOTPLUG_EN (0x00061110): 0x10000000
PORT_HOTPLUG_STAT (0x00061114): 0x10000000
PORT_HOTPLUG_EN (0x00061110): 0x20000000
PORT_HOTPLUG_STAT (0x00061114): 0x00000000
So the enable bit and live state bit always match 1:1.
Acked-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/display/g4x_dp.c | 28 +--------------------------
drivers/gpu/drm/i915/i915_reg.h | 13 +------------
2 files changed, 2 insertions(+), 39 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/g4x_dp.c b/drivers/gpu/drm/i915/display/g4x_dp.c
index a50ad0fff57c..920d570f7594 100644
--- a/drivers/gpu/drm/i915/display/g4x_dp.c
+++ b/drivers/gpu/drm/i915/display/g4x_dp.c
@@ -1197,29 +1197,6 @@ static bool g4x_digital_port_connected(struct intel_encoder *encoder)
return intel_de_read(dev_priv, PORT_HOTPLUG_STAT) & bit;
}
-static bool gm45_digital_port_connected(struct intel_encoder *encoder)
-{
- struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
- u32 bit;
-
- switch (encoder->hpd_pin) {
- case HPD_PORT_B:
- bit = PORTB_HOTPLUG_LIVE_STATUS_GM45;
- break;
- case HPD_PORT_C:
- bit = PORTC_HOTPLUG_LIVE_STATUS_GM45;
- break;
- case HPD_PORT_D:
- bit = PORTD_HOTPLUG_LIVE_STATUS_GM45;
- break;
- default:
- MISSING_CASE(encoder->hpd_pin);
- return false;
- }
-
- return intel_de_read(dev_priv, PORT_HOTPLUG_STAT) & bit;
-}
-
static bool ilk_digital_port_connected(struct intel_encoder *encoder)
{
struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
@@ -1384,10 +1361,7 @@ bool g4x_dp_init(struct drm_i915_private *dev_priv,
dig_port->hpd_pulse = intel_dp_hpd_pulse;
if (HAS_GMCH(dev_priv)) {
- if (IS_GM45(dev_priv))
- dig_port->connected = gm45_digital_port_connected;
- else
- dig_port->connected = g4x_digital_port_connected;
+ dig_port->connected = g4x_digital_port_connected;
} else {
if (port == PORT_A)
dig_port->connected = ilk_digital_port_connected;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index c1efa655fb68..de58695ad1c0 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2483,18 +2483,7 @@
#define CRT_HOTPLUG_DETECT_VOLTAGE_475MV (1 << 2)
#define PORT_HOTPLUG_STAT _MMIO(DISPLAY_MMIO_BASE(dev_priv) + 0x61114)
-/*
- * HDMI/DP bits are g4x+
- *
- * WARNING: Bspec for hpd status bits on gen4 seems to be completely confused.
- * Please check the detailed lore in the commit message for for experimental
- * evidence.
- */
-/* Bspec says GM45 should match G4X/VLV/CHV, but reality disagrees */
-#define PORTD_HOTPLUG_LIVE_STATUS_GM45 (1 << 29)
-#define PORTC_HOTPLUG_LIVE_STATUS_GM45 (1 << 28)
-#define PORTB_HOTPLUG_LIVE_STATUS_GM45 (1 << 27)
-/* G4X/VLV/CHV DP/HDMI bits again match Bspec */
+/* HDMI/DP bits are g4x+ */
#define PORTD_HOTPLUG_LIVE_STATUS_G4X (1 << 27)
#define PORTC_HOTPLUG_LIVE_STATUS_G4X (1 << 28)
#define PORTB_HOTPLUG_LIVE_STATUS_G4X (1 << 29)
--
2.39.2
