On Wed, Jun 21, 2023 at 11:00:31AM +0300, Jani Nikula wrote:
> On Tue, 20 Jun 2023, Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx> wrote:
> > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> >
> > Stop with the VBT AUX CH sanitation, and instead just check
> > that the appropriate AUX CH is still available when initializing
> > a DP/TC port.
> >
> > Note that the old way of sanitizing gave priority to the last
> > port declared in the VBT, but now we sort of do the opposite by
> > favoring the first encoder to succesfully initialize. The reason
> > for the old "last port wins" preference was eg. Asrock B250M-HDV
> > where port A (eDP) and port E (DP->VGA) have an AUX CH conflict
> > and we need to prefer port E. However with the new way port A (eDP)
> > will be probed first, but will fail to probe due to HPD and thus
> > port E will still win in the end.
>
> That's the kind of explanation I was after in the previous patch for ddc
> pin.
I think I lost a bit of explanations on account of squashing
away one one entire patch from the original series. Suppose
I should add more text to both of these sanitation patches
to explain the reasoning a bit better...
>
> Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Ta.
>
> >
> > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/display/g4x_dp.c | 3 ++
> > drivers/gpu/drm/i915/display/intel_bios.c | 53 ---------------------
> > drivers/gpu/drm/i915/display/intel_ddi.c | 5 +-
> > drivers/gpu/drm/i915/display/intel_dp_aux.c | 51 ++++++++++++++++----
> > 4 files changed, 50 insertions(+), 62 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/g4x_dp.c b/drivers/gpu/drm/i915/display/g4x_dp.c
> > index 0cab5992e3da..4c7187f7913e 100644
> > --- a/drivers/gpu/drm/i915/display/g4x_dp.c
> > +++ b/drivers/gpu/drm/i915/display/g4x_dp.c
> > @@ -1378,6 +1378,9 @@ bool g4x_dp_init(struct drm_i915_private *dev_priv,
> > intel_infoframe_init(dig_port);
> >
> > dig_port->aux_ch = intel_dp_aux_ch(intel_encoder);
> > + if (dig_port->aux_ch == AUX_CH_NONE)
> > + goto err_init_connector;
> > +
> > if (!intel_dp_init_connector(dig_port, intel_connector))
> > goto err_init_connector;
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
> > index 439ab5b3cbe5..d1bf725ee9b3 100644
> > --- a/drivers/gpu/drm/i915/display/intel_bios.c
> > +++ b/drivers/gpu/drm/i915/display/intel_bios.c
> > @@ -2230,56 +2230,6 @@ static u8 map_ddc_pin(struct drm_i915_private *i915, u8 vbt_pin)
> > return 0;
> > }
> >
> > -static enum port get_port_by_aux_ch(struct drm_i915_private *i915, u8 aux_ch)
> > -{
> > - enum port port;
> > -
> > - if (!aux_ch)
> > - return PORT_NONE;
> > -
> > - for_each_port(port) {
> > - const struct intel_bios_encoder_data *devdata =
> > - i915->display.vbt.ports[port];
> > -
> > - if (devdata && aux_ch == devdata->child.aux_channel)
> > - return port;
> > - }
> > -
> > - return PORT_NONE;
> > -}
> > -
> > -static void sanitize_aux_ch(struct intel_bios_encoder_data *devdata,
> > - enum port port)
> > -{
> > - struct drm_i915_private *i915 = devdata->i915;
> > - struct child_device_config *child;
> > - enum port p;
> > -
> > - p = get_port_by_aux_ch(i915, devdata->child.aux_channel);
> > - if (p == PORT_NONE)
> > - return;
> > -
> > - drm_dbg_kms(&i915->drm,
> > - "port %c trying to use the same AUX CH (0x%x) as port %c, "
> > - "disabling port %c DP support\n",
> > - port_name(port), devdata->child.aux_channel,
> > - port_name(p), port_name(p));
> > -
> > - /*
> > - * If we have multiple ports supposedly sharing the aux channel, then DP
> > - * couldn't exist on the shared port. Otherwise they share the same aux
> > - * channel and system couldn't communicate with them separately.
> > - *
> > - * Give inverse child device order the priority, last one wins. Yes,
> > - * there are real machines (eg. Asrock B250M-HDV) where VBT has both
> > - * port A and port E with the same AUX ch and we must pick port E :(
> > - */
> > - child = &i915->display.vbt.ports[p]->child;
> > -
> > - child->device_type &= ~DEVICE_TYPE_DISPLAYPORT_OUTPUT;
> > - child->aux_channel = 0;
> > -}
> > -
> > static u8 dvo_port_type(u8 dvo_port)
> > {
> > switch (dvo_port) {
> > @@ -2687,9 +2637,6 @@ static void parse_ddi_port(struct intel_bios_encoder_data *devdata)
> >
> > sanitize_device_type(devdata, port);
> >
> > - if (intel_bios_encoder_supports_dp(devdata))
> > - sanitize_aux_ch(devdata, port);
> > -
> > i915->display.vbt.ports[port] = devdata;
> > }
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> > index 662b5ceef3c8..9e4e6482aa26 100644
> > --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> > @@ -4938,8 +4938,11 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
> > dig_port->dp.output_reg = INVALID_MMIO_REG;
> > dig_port->max_lanes = intel_ddi_max_lanes(dig_port);
> >
> > - if (need_aux_ch(encoder, init_dp))
> > + if (need_aux_ch(encoder, init_dp)) {
> > dig_port->aux_ch = intel_dp_aux_ch(encoder);
> > + if (dig_port->aux_ch == AUX_CH_NONE)
> > + goto err;
> > + }
> >
> > if (intel_phy_is_tc(dev_priv, phy)) {
> > bool is_legacy =
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.c b/drivers/gpu/drm/i915/display/intel_dp_aux.c
> > index 21b50a5c8a85..2d173bd495a3 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp_aux.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp_aux.c
> > @@ -792,25 +792,60 @@ static enum aux_ch default_aux_ch(struct intel_encoder *encoder)
> > return (enum aux_ch)encoder->port;
> > }
> >
> > +static struct intel_encoder *
> > +get_encoder_by_aux_ch(struct intel_encoder *encoder,
> > + enum aux_ch aux_ch)
> > +{
> > + struct drm_i915_private *i915 = to_i915(encoder->base.dev);
> > + struct intel_encoder *other;
> > +
> > + for_each_intel_encoder(&i915->drm, other) {
> > + if (other == encoder)
> > + continue;
> > +
> > + if (!intel_encoder_is_dig_port(other))
> > + continue;
> > +
> > + if (enc_to_dig_port(other)->aux_ch == aux_ch)
> > + return other;
> > + }
> > +
> > + return NULL;
> > +}
> > +
> > enum aux_ch intel_dp_aux_ch(struct intel_encoder *encoder)
> > {
> > struct drm_i915_private *i915 = to_i915(encoder->base.dev);
> > + struct intel_encoder *other;
> > + const char *source;
> > enum aux_ch aux_ch;
> >
> > aux_ch = intel_bios_dp_aux_ch(encoder->devdata);
> > - if (aux_ch != AUX_CH_NONE) {
> > - drm_dbg_kms(&i915->drm, "[ENCODER:%d:%s] using AUX %c (VBT)\n",
> > - encoder->base.base.id, encoder->base.name,
> > - aux_ch_name(aux_ch));
> > - return aux_ch;
> > + source = "VBT";
> > +
> > + if (aux_ch == AUX_CH_NONE) {
> > + aux_ch = default_aux_ch(encoder);
> > + source = "platform default";
> > }
> >
> > - aux_ch = default_aux_ch(encoder);
> > + if (aux_ch == AUX_CH_NONE)
> > + return AUX_CH_NONE;
> > +
> > + /* FIXME validate aux_ch against platform caps */
> > +
> > + other = get_encoder_by_aux_ch(encoder, aux_ch);
> > + if (other) {
> > + drm_dbg_kms(&i915->drm,
> > + "[ENCODER:%d:%s] AUX CH %c already claimed by [ENCODER:%d:%s]\n",
> > + encoder->base.base.id, encoder->base.name, aux_ch_name(aux_ch),
> > + other->base.base.id, other->base.name);
> > + return AUX_CH_NONE;
> > + }
> >
> > drm_dbg_kms(&i915->drm,
> > - "[ENCODER:%d:%s] using AUX %c (platform default)\n",
> > + "[ENCODER:%d:%s] Using AUX CH %c (%s)\n",
> > encoder->base.base.id, encoder->base.name,
> > - aux_ch_name(aux_ch));
> > + aux_ch_name(aux_ch), source);
> >
> > return aux_ch;
> > }
>
> --
> Jani Nikula, Intel Open Source Graphics Center
--
Ville Syrjälä
Intel
