From: Ville Syrjälä ville.syrjala@linux.intel.com
The icl+ power well code currently assumes that every AUX power well maps to an encoder which is using said power well. That is by no menas guaranteed as we: - only register encoders for ports declared in the VBT - combo PHY HDMI-only encoder no longer get an AUX CH since commit 9856308c94ca ("drm/i915: Only populate aux_ch if really needed")
However we have places such as intel_power_domains_sanitize_state() that blindly traverse all the possible power wells. So these bits of code may very well encounbter an aux power well with no associated encoder.
In this particular case the BIOS seems to have left one AUX power well enabled even though we're dealing with a HDMI only encoder on a combo PHY. We then proceed to turn off said power well and explode when we can't find a matching encoder. As a short term fix we should be able to just skip the PHY related parts of the power well programming since we know this situation can only happen with combo PHYs.
Another option might be to go back to always picking an AUX CH for all encoders. However I'm a bit wary about that since we might in theory end up conflicting with the VBT AUX CH assignment. Also that wouldn't help with encoders not declared in the VBT, should we ever need to poke the corresponding power wells.
Longer term we need to figure out what the actual relationship is between the PHY vs. AUX CH vs. AUX power well. Currently this is entirely unclear.
Cc: stable@vger.kernel.org Fixes: 9856308c94ca ("drm/i915: Only populate aux_ch if really needed") Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/10184 Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com --- .../drm/i915/display/intel_display_power_well.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_display_power_well.c b/drivers/gpu/drm/i915/display/intel_display_power_well.c index 47cd6bb04366..06900ff307b2 100644 --- a/drivers/gpu/drm/i915/display/intel_display_power_well.c +++ b/drivers/gpu/drm/i915/display/intel_display_power_well.c @@ -246,7 +246,14 @@ static enum phy icl_aux_pw_to_phy(struct drm_i915_private *i915, enum aux_ch aux_ch = icl_aux_pw_to_ch(power_well); struct intel_digital_port *dig_port = aux_ch_to_digital_port(i915, aux_ch);
- return intel_port_to_phy(i915, dig_port->base.port); + /* + * FIXME should we care about the (VBT defined) dig_port->aux_ch + * relationship or should this be purely defined by the hardware layout? + * Currently if the port doesn't appear in the VBT, or if it's declared + * as HDMI-only and routed to a combo PHY, the encoder either won't be + * present at all or it will not have an aux_ch assigned. + */ + return dig_port ? intel_port_to_phy(i915, dig_port->base.port) : PHY_NONE; }
static void hsw_wait_for_power_well_enable(struct drm_i915_private *dev_priv, @@ -414,7 +421,8 @@ icl_combo_phy_aux_power_well_enable(struct drm_i915_private *dev_priv,
intel_de_rmw(dev_priv, regs->driver, 0, HSW_PWR_WELL_CTL_REQ(pw_idx));
- if (DISPLAY_VER(dev_priv) < 12) + /* FIXME this is a mess */ + if (phy != PHY_NONE) intel_de_rmw(dev_priv, ICL_PORT_CL_DW12(phy), 0, ICL_LANE_ENABLE_AUX);
@@ -437,7 +445,10 @@ icl_combo_phy_aux_power_well_disable(struct drm_i915_private *dev_priv,
drm_WARN_ON(&dev_priv->drm, !IS_ICELAKE(dev_priv));
- intel_de_rmw(dev_priv, ICL_PORT_CL_DW12(phy), ICL_LANE_ENABLE_AUX, 0); + /* FIXME this is a mess */ + if (phy != PHY_NONE) + intel_de_rmw(dev_priv, ICL_PORT_CL_DW12(phy), + ICL_LANE_ENABLE_AUX, 0);
intel_de_rmw(dev_priv, regs->driver, HSW_PWR_WELL_CTL_REQ(pw_idx), 0);