Commit 424f109f authored by Imre Deak's avatar Imre Deak
Browse files

drm/i915: Handle the TCCOLD power-down event 



Based on a recent BSpec update (Index/21750) we must handle the TCCOLD
event associated with the DP-alt mode. We can detect this event by
reading an invalid all-1s value from FIA registers.

After detecting TCCOLD we will:
- fall back to TBT-alt mode when attempting to switch to DP-alt mode
- conclude that nothing is connected during live status detection
- WARN when already in unsafe mode, since then TCCOLD is unexpected

v2:
- Use DRM_DEBUG_KMS instead of DRM_DEBUG_DRIVER. (José)
v3:
- Use 0xffffffff instead of -1 as invalid FIA reg value.
  (José, Ville)
- Check for TCCOLD in icl_tc_phy_status_complete() too. (Ville)

Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: default avatarImre Deak <imre.deak@intel.com>
Reviewed-by: default avatarJosé Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190628143635.22066-12-imre.deak@intel.com
parent ddec3627

drivers/gpu/drm/i915/display/intel_tc.c

+29 −4
Original line number Diff line number Diff line
@@ -29,6 +29,8 @@ u32 intel_tc_port_get_lane_mask(struct intel_digital_port *dig_port) 


	lane_mask = I915_READ(PORT_TX_DFLEXDPSP);



	WARN_ON(lane_mask == 0xffffffff);



	return (lane_mask & DP_LANE_ASSIGNMENT_MASK(tc_port)) >>

	       DP_LANE_ASSIGNMENT_SHIFT(tc_port);

}
@@ -92,6 +94,12 @@ static u32 tc_port_live_status_mask(struct intel_digital_port *dig_port) 


	val = I915_READ(PORT_TX_DFLEXDPSP);



	if (val == 0xffffffff) {

		DRM_DEBUG_KMS("Port %s: PHY in TCCOLD, nothing connected\n",

			      dig_port->tc_port_name);

		return mask;

	}



	if (val & TC_LIVE_STATE_TBT(tc_port))

		mask |= BIT(TC_PORT_TBT_ALT);

	if (val & TC_LIVE_STATE_TC(tc_port))
@@ -111,12 +119,19 @@ static bool icl_tc_phy_status_complete(struct intel_digital_port *dig_port) 
{

	struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);

	enum tc_port tc_port = intel_port_to_tc(dev_priv, dig_port->base.port);

	u32 val;



	return I915_READ(PORT_TX_DFLEXDPPMS) &

	       DP_PHY_MODE_STATUS_COMPLETED(tc_port);

	val = I915_READ(PORT_TX_DFLEXDPPMS);

	if (val == 0xffffffff) {

		DRM_DEBUG_KMS("Port %s: PHY in TCCOLD, assuming not complete\n",

			      dig_port->tc_port_name);

		return false;

	}



static void icl_tc_phy_set_safe_mode(struct intel_digital_port *dig_port,

	return val & DP_PHY_MODE_STATUS_COMPLETED(tc_port);

}



static bool icl_tc_phy_set_safe_mode(struct intel_digital_port *dig_port,

				     bool enable)

{

	struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
@@ -124,6 +139,13 @@ static void icl_tc_phy_set_safe_mode(struct intel_digital_port *dig_port, 
	u32 val;



	val = I915_READ(PORT_TX_DFLEXDPCSSS);

	if (val == 0xffffffff) {

		DRM_DEBUG_KMS("Port %s: PHY in TCCOLD, can't set safe-mode to %s\n",

			      dig_port->tc_port_name,

			      enableddisabled(enable));



		return false;

	}



	val &= ~DP_PHY_MODE_STATUS_NOT_SAFE(tc_port);

	if (!enable)
@@ -134,6 +156,8 @@ static void icl_tc_phy_set_safe_mode(struct intel_digital_port *dig_port, 
	if (enable && wait_for(!icl_tc_phy_status_complete(dig_port), 10))

		DRM_DEBUG_KMS("Port %s: PHY complete clear timed out\n",

			      dig_port->tc_port_name);



	return true;

}



/*
@@ -172,7 +196,8 @@ static bool icl_tc_phy_connect(struct intel_digital_port *dig_port) 
		return false;

	}



	icl_tc_phy_set_safe_mode(dig_port, false);

	if (!icl_tc_phy_set_safe_mode(dig_port, false))

		return false;



	if (dig_port->tc_mode == TC_PORT_LEGACY)

		return true;

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