On Tue, Jun 25, 2019 at 04:17:35PM +0300, Ville Syrjälä wrote: > On Thu, Jun 20, 2019 at 05:05:48PM +0300, Imre Deak wrote: > > 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) > > We don't seem to care about the all 1s in icl_tc_phy_status_complete() > and icl_tc_phy_is_in_safe_mode(). Is that OK?
Err, probably not ok, thanks for spotting it. The cirumstances when and why "TCCOLD" would be entered is badly specified and imo a bad HW interface (the driver doesn't seem to have any control of it, the state will be just entered). My best guess is that only the DP-alt mode specific parts power down in the TCCOLD state and when that happens the TBT-alt mode is still operational. Based on the above assumption (and that safe-mode=TBT-alt unsafe-mode=DP-alt/legacy), I can change icl_tc_phy_state_complete() to return false and icl_tc_phy_is_in_safe_mode() to return true if they detect the TCCOLD state, also adding a debug log about these events. > > > > > Cc: José Roberto de Souza <[email protected]> > > Cc: Rodrigo Vivi <[email protected]> > > Cc: Ville Syrjälä <[email protected]> > > Signed-off-by: Imre Deak <[email protected]> > > --- > > drivers/gpu/drm/i915/display/intel_tc.c | 23 +++++++++++++++++++++-- > > 1 file changed, 21 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_tc.c > > b/drivers/gpu/drm/i915/display/intel_tc.c > > index a02513814392..fffe4c4a6602 100644 > > --- a/drivers/gpu/drm/i915/display/intel_tc.c > > +++ b/drivers/gpu/drm/i915/display/intel_tc.c > > @@ -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 == -1); > > + > > return (lane_mask & DP_LANE_ASSIGNMENT_MASK(tc_port)) >> > > DP_LANE_ASSIGNMENT_SHIFT(tc_port); > > } > > @@ -89,6 +91,12 @@ static u32 tc_port_live_status_mask(struct > > intel_digital_port *dig_port) > > > > val = I915_READ(PORT_TX_DFLEXDPSP); > > > > + if (val == -1) { > > Not sure I like this -1 use. I don't think we typically use it elsewhere > in similar context. Heh, was also voted down by José. I will use then (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)) > > @@ -113,7 +121,7 @@ static bool icl_tc_phy_status_complete(struct > > intel_digital_port *dig_port) > > DP_PHY_MODE_STATUS_COMPLETED(tc_port); > > } > > > > -static void icl_tc_phy_set_safe_mode(struct intel_digital_port *dig_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); > > @@ -122,6 +130,14 @@ static void icl_tc_phy_set_safe_mode(struct > > intel_digital_port *dig_port, > > > > val = I915_READ(PORT_TX_DFLEXDPCSSS); > > > > + if (val == -1) { > > + 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) > > val |= DP_PHY_MODE_STATUS_NOT_SAFE(tc_port); > > @@ -131,6 +147,8 @@ 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; > > } > > > > /* > > @@ -169,7 +187,8 @@ 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; > > -- > > 2.17.1 > > -- > Ville Syrjälä > Intel _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
