Re: [PATCH 6/6 v3] drm/i915: Enable HDMI on DDI-E

Zhang, Xiong Y
2015-08-13T02:57:42Z

> On Wed, Aug 12, 2015 at 06:39:34PM +0800, Xiong Zhang wrote:
> > DDI-E doesn't have the correspondent GMBUS pin.
> >
> > We rely on VBT to tell us which one it being used instead.
> >
> > The DVI/HDMI on shared port couldn't exist.
> >
> > This patch isn't tested without hardware wchich has HDMI on DDI-E.
> >
> > v2: fix trailing whitespace
> > v3: WARN() take place of BUG()
>
> I asked for MISSING_CASE, not WARN.
> -Daniel
[Zhang, Xiong Y] Because DDI-E on SKL doesn't have correspondent GMBUS pin, it should share such pin with DDI-B/C/D. We don't know the default GMBUS pin for DDI-E if VBT doesn't tell us.
If VBT don't tell us or give us an invalid GMBUS pin, driver will fail in getting HDMI info. In such case, we really need a warn which tell us why driver couldn't read EDID info for HDMI on DDI-E.

thanks
>
> >
> > Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.com>
> > Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> > ---
> > drivers/gpu/drm/i915/i915_drv.h | 5 +++++
> > drivers/gpu/drm/i915/intel_bios.c | 25 +++++++++++++++++++++----
> > drivers/gpu/drm/i915/intel_hdmi.c | 18 ++++++++++++++++++
> > 3 files changed, 44 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h
> > b/drivers/gpu/drm/i915/i915_drv.h index 6d93334..5d8e7fe 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -1414,6 +1414,10 @@ enum modeset_restore { #define DP_AUX_C
> 0x20
> > #define DP_AUX_D 0x30
> >
> > +#define DDC_PIN_B 0x05
> > +#define DDC_PIN_C 0x04
> > +#define DDC_PIN_D 0x06
> > +
> > struct ddi_vbt_port_info {
> > /*
> > * This is an index in the HDMI/DVI DDI buffer translation table.
> > @@ -1428,6 +1432,7 @@ struct ddi_vbt_port_info {
> > uint8_t supports_dp:1;
> >
> > uint8_t alternate_aux_channel;
> > + uint8_t alternate_ddc_pin;
> > };
> >
> > enum psr_lines_to_wait {
> > diff --git a/drivers/gpu/drm/i915/intel_bios.c
> > b/drivers/gpu/drm/i915/intel_bios.c
> > index 16cdf17..8140531 100644
> > --- a/drivers/gpu/drm/i915/intel_bios.c
> > +++ b/drivers/gpu/drm/i915/intel_bios.c
> > @@ -894,7 +894,7 @@ static void parse_ddi_port(struct drm_i915_private
> *dev_priv, enum port port,
> > uint8_t hdmi_level_shift;
> > int i, j;
> > bool is_dvi, is_hdmi, is_dp, is_edp, is_crt;
> > - uint8_t aux_channel;
> > + uint8_t aux_channel, ddc_pin;
> > /* Each DDI port can have more than one value on the "DVO Port" field,
> > * so look for all the possible values for each port and abort if more
> > * than one is found. */
> > @@ -928,6 +928,7 @@ static void parse_ddi_port(struct drm_i915_private
> *dev_priv, enum port port,
> > return;
> >
> > aux_channel = child->raw[25];
> > + ddc_pin = child->common.ddc_pin;
> >
> > is_dvi = child->common.device_type &
> DEVICE_TYPE_TMDS_DVI_SIGNALING;
> > is_dp = child->common.device_type &
> DEVICE_TYPE_DISPLAYPORT_OUTPUT;
> > @@ -959,11 +960,27 @@ static void parse_ddi_port(struct
> drm_i915_private *dev_priv, enum port port,
> > DRM_DEBUG_KMS("Port %c is internal DP\n", port_name(port));
> >
> > if (is_dvi) {
> > - if (child->common.ddc_pin == 0x05 && port != PORT_B)
> > + if (port == PORT_E) {
> > + info->alternate_ddc_pin = ddc_pin;
> > + /* if DDIE share ddc pin with other port, then
> > + * dvi/hdmi couldn't exist on the shared port.
> > + * Otherwise they share the same ddc bin and system
> > + * couldn't communicate with them seperately. */
> > + if (ddc_pin == DDC_PIN_B) {
> > + dev_priv->vbt.ddi_port_info[PORT_B].supports_dvi = 0;
> > + dev_priv->vbt.ddi_port_info[PORT_B].supports_hdmi = 0;
> > + } else if (ddc_pin == DDC_PIN_C) {
> > + dev_priv->vbt.ddi_port_info[PORT_C].supports_dvi = 0;
> > + dev_priv->vbt.ddi_port_info[PORT_C].supports_hdmi = 0;
> > + } else if (ddc_pin == DDC_PIN_D) {
> > + dev_priv->vbt.ddi_port_info[PORT_D].supports_dvi = 0;
> > + dev_priv->vbt.ddi_port_info[PORT_D].supports_hdmi = 0;
> > + }
> > + } else if (ddc_pin == DDC_PIN_B && port != PORT_B)
> > DRM_DEBUG_KMS("Unexpected DDC pin for port B\n");
> > - if (child->common.ddc_pin == 0x04 && port != PORT_C)
> > + else if (ddc_pin == DDC_PIN_C && port != PORT_C)
> > DRM_DEBUG_KMS("Unexpected DDC pin for port C\n");
> > - if (child->common.ddc_pin == 0x06 && port != PORT_D)
> > + else if (ddc_pin == DDC_PIN_D && port != PORT_D)
> > DRM_DEBUG_KMS("Unexpected DDC pin for port D\n");
> > }
> >
> > diff --git a/drivers/gpu/drm/i915/intel_hdmi.c
> > b/drivers/gpu/drm/i915/intel_hdmi.c
> > index 70bad5b..a4129f2 100644
> > --- a/drivers/gpu/drm/i915/intel_hdmi.c
> > +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> > @@ -1991,6 +1991,24 @@ void intel_hdmi_init_connector(struct
> intel_digital_port *intel_dig_port,
> > intel_hdmi->ddc_bus = GMBUS_PIN_DPD;
> > intel_encoder->hpd_pin = HPD_PORT_D;
> > break;
> > + case PORT_E:
> > + /* On SKL PORT E doesn't have seperate GMBUS pin
> > + * We rely on VBT to set a proper alternate GMBUS pin. */
> > + switch (dev_priv->vbt.ddi_port_info[PORT_E].alternate_ddc_pin) {
> > + case DDC_PIN_B:
> > + intel_hdmi->ddc_bus = GMBUS_PIN_DPB;
> > + break;
> > + case DDC_PIN_C:
> > + intel_hdmi->ddc_bus = GMBUS_PIN_DPC;
> > + break;
> > + case DDC_PIN_D:
> > + intel_hdmi->ddc_bus = GMBUS_PIN_DPD;
> > + break;
> > + default:
> > + WARN(1, "VBT assign invalid DDC PIN for HDMI on
> PORT_E.\n");
> > + }
> > + intel_encoder->hpd_pin = HPD_PORT_E;
> > + break;
> > case PORT_A:
> > intel_encoder->hpd_pin = HPD_PORT_A;
> > /* Internal port only for eDP. */
> > --
> > 2.1.4
> >
> > _______________________________________________
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> > Intel-gfx@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch