On Tue, Jun 18, 2019 at 10:30:06AM -0700, Matt Roper wrote: > On Tue, Jun 18, 2019 at 07:08:55PM +0300, Ville Syrjälä wrote: > > On Mon, Jun 17, 2019 at 04:48:10PM -0700, Matt Roper wrote: > > > EHL has a mux on combo PHY A that allows it to be driven either by an > > > internal display (DDI-A or DSI DPHY) or by an external display (DDI-D). > > > This is a motherboard design decision that can not be changed on the > > > fly. Unfortunately there are no strap registers that allow us to detect > > > the board configuration directly, so let's use the VBT to try to figure > > > it out and program the mux accordingly. > > > > > > v2: > > > - Confirmed that VBT's dvo port refers to the DDI and not the PHY. > > > Thus we can check more explicitly for (ddi_d && !(ddi_a || dsi)). If > > > a bad VBT contradicts itself, let internal display win. (Ville) > > > > > > Cc: Clint Taylor <clinton.a.tay...@intel.com> > > > Cc: Ville Syrjälä <ville.syrj...@linux.intel.com> > > > Signed-off-by: Matt Roper <matthew.d.ro...@intel.com> > > > --- > > > drivers/gpu/drm/i915/display/intel_bios.c | 3 ++ > > > .../gpu/drm/i915/display/intel_combo_phy.c | 36 +++++++++++++++++++ > > > drivers/gpu/drm/i915/i915_reg.h | 1 + > > > 3 files changed, 40 insertions(+) > > > > > > diff --git a/drivers/gpu/drm/i915/display/intel_bios.c > > > b/drivers/gpu/drm/i915/display/intel_bios.c > > > index c4710889cb32..0c9808132d67 100644 > > > --- a/drivers/gpu/drm/i915/display/intel_bios.c > > > +++ b/drivers/gpu/drm/i915/display/intel_bios.c > > > @@ -1668,6 +1668,9 @@ parse_general_definitions(struct drm_i915_private > > > *dev_priv, > > > if (!child->device_type) > > > continue; > > > > > > + DRM_DEBUG_KMS("Found VBT child device with type 0x%x\n", > > > + child->device_type); > > > + > > > > Was this hunk intentional? > > > > Yeah, I figured that having a little more detail on the child device > details will probably be useful for debugging any cases where the VBT > seems to contradict itself. I'll add a note about the debug message to > the commit message to make it clear it's intentional. > > > > > /* > > > * Copy as much as we know (sizeof) and is available > > > * (child_dev_size) of the child device. Accessing the data must > > > diff --git a/drivers/gpu/drm/i915/display/intel_combo_phy.c > > > b/drivers/gpu/drm/i915/display/intel_combo_phy.c > > > index 841708da5a56..c18079a09a2e 100644 > > > --- a/drivers/gpu/drm/i915/display/intel_combo_phy.c > > > +++ b/drivers/gpu/drm/i915/display/intel_combo_phy.c > > > @@ -260,6 +260,32 @@ void intel_combo_phy_power_up_lanes(struct > > > drm_i915_private *dev_priv, > > > I915_WRITE(ICL_PORT_CL_DW10(port), val); > > > } > > > > > > +static u32 ehl_combo_phy_a_mux(struct drm_i915_private *i915, u32 val) > > > +{ > > > + bool ddi_a_present = i915->vbt.ddi_port_info[PORT_A].child != NULL; > > > + bool ddi_d_present = i915->vbt.ddi_port_info[PORT_D].child != NULL; > > > + bool dsi_present = intel_bios_is_dsi_present(i915, NULL); > > > + > > > + /* > > > + * VBT's 'dvo port' field for child devices references the DDI, not > > > + * the PHY. So if combo PHY A is wired up to drive an external > > > + * display, we should see a child device present on PORT_D and > > > + * nothing on PORT_A and no DSI. > > > + */ > > > + if (ddi_d_present && !ddi_a_present && !dsi_present) > > > + return val | ICL_PHY_MISC_MUX_DDID; > > > + > > > + /* > > > + * If we encounter a VBT that claims to have an external display on > > > + * DDI-D _and_ an internal display on DDI-A/DSI leave an error message > > > + * in the log and let the internal display win. > > > + */ > > > + if (ddi_d_present) > > > + DRM_ERROR("VBT claims to have both internal and external > > > displays on PHY A. Configuring for internal.\n"); > > > + > > > + return val & ~ICL_PHY_MISC_MUX_DDID; > > > +} > > > + > > > static void icl_combo_phys_init(struct drm_i915_private *dev_priv) > > > { > > > enum port port; > > > @@ -273,7 +299,17 @@ static void icl_combo_phys_init(struct > > > drm_i915_private *dev_priv) > > > continue; > > > } > > > > > > + /* > > > + * EHL's combo PHY A can be hooked up to either an external > > > + * display (via DDI-D) or an internal display (via DDI-A or > > > + * the DSI DPHY). This is a motherboard design decision that > > > + * can't be changed on the fly, so initialize the PHY's mux > > > + * based on whether our VBT indicates the presence of any > > > + * "internal" child devices. > > > + */ > > > val = I915_READ(ICL_PHY_MISC(port)); > > > + if (!IS_ICELAKE(dev_priv) && port == PORT_A) > > > > Maybe IS_EHL instead? > > That's how I was originally going to write it, but I switched it to !icl > to follow the general convention of "assume future platforms inherit all > behavior of current platform."
This feels like a one off cost saving measure to me. So not entirely sure it makes sense to assume future platforms would follow this apporach. > > > Matt > > > > > Patch is > > Reviewed-by: Ville Syrjälä <ville.syrj...@linux.intel.com> > > > > > + val = ehl_combo_phy_a_mux(dev_priv, val); > > > val &= ~ICL_PHY_MISC_DE_IO_COMP_PWR_DOWN; > > > I915_WRITE(ICL_PHY_MISC(port), val); > > > > > > diff --git a/drivers/gpu/drm/i915/i915_reg.h > > > b/drivers/gpu/drm/i915/i915_reg.h > > > index 1ae36b9efc85..68afafafd312 100644 > > > --- a/drivers/gpu/drm/i915/i915_reg.h > > > +++ b/drivers/gpu/drm/i915/i915_reg.h > > > @@ -11138,6 +11138,7 @@ enum skl_power_gate { > > > #define _ICL_PHY_MISC_B 0x64C04 > > > #define ICL_PHY_MISC(port) _MMIO_PORT(port, _ICL_PHY_MISC_A, \ > > > _ICL_PHY_MISC_B) > > > +#define ICL_PHY_MISC_MUX_DDID (1 << 28) > > > #define ICL_PHY_MISC_DE_IO_COMP_PWR_DOWN (1 << 23) > > > > > > /* Icelake Display Stream Compression Registers */ > > > -- > > > 2.17.2 > > > > -- > > Ville Syrjälä > > Intel > > -- > Matt Roper > Graphics Software Engineer > IoTG Platform Enabling & Development > Intel Corporation > (916) 356-2795 -- Ville Syrjälä Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx