> On Tue, 2015-08-11 at 07:05 +0000, Zhang, Xiong Y wrote: > > > -----Original Message----- > > > From: Vivi, Rodrigo > > > Sent: Saturday, August 8, 2015 8:34 AM > > > To: intel-gfx@lists.freedesktop.org > > > Cc: Vivi, Rodrigo; Zhang, Xiong Y > > > Subject: [PATCH 7/6] drm/i915/skl: DDI-E and DDI-A shares 4 lanes. > > > > > > DDI-A and DDI-E shares the 4 lanes. So when DDI-E is present we need > > > to configure lane count propperly for both. > > > > > > This was based on Sonika's > > > [PATCH] drm/i915/skl: Select DDIA lane capability based upon vbt > > > > > > Credits-to: Sonika Jindal <sonika.jin...@intel.com> > > > Cc: Xiong Zhang <xiong.y.zh...@intel.com> > > > Signed-off-by: Rodrigo Vivi <rodrigo.v...@intel.com> > > > --- > > > drivers/gpu/drm/i915/intel_ddi.c | 12 ++++++++++-- > > > drivers/gpu/drm/i915/intel_dp.c | 8 +++++--- > > > 2 files changed, 15 insertions(+), 5 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/i915/intel_ddi.c > > > b/drivers/gpu/drm/i915/intel_ddi.c > > > index 110d546..557cecf 100644 > > > --- a/drivers/gpu/drm/i915/intel_ddi.c > > > +++ b/drivers/gpu/drm/i915/intel_ddi.c > > > @@ -3178,7 +3178,15 @@ void intel_ddi_init(struct drm_device *dev, > > > enum port port) > > > struct intel_digital_port *intel_dig_port; > > > struct intel_encoder *intel_encoder; > > > struct drm_encoder *encoder; > > > - bool init_hdmi, init_dp; > > > + bool init_hdmi, init_dp, ddi_e_present; > > > + > > > + /* > > > + * On SKL we don't have a way to detect DDI-E so we rely > > > on VBT. > > > + */ > > > + ddie_present = IS_SKYLAKE(dev) && > > > + (dev_priv->vbt.ddi_port_info[PORT_E].supports_dp > > > || > > > + dev_priv->vbt.ddi_port_info[PORT_E].supports_dvi > > > || > > > + dev_priv > > > ->vbt.ddi_port_info[PORT_E].supports_hdmi); > > [Zhang, Xiong Y] ddie_present should be ddi_e_present > > > > > > init_hdmi = (dev_priv > > > ->vbt.ddi_port_info[port].supports_dvi || > > > dev_priv > > > ->vbt.ddi_port_info[port].supports_hdmi); > > > @@ -3210,7 +3218,7 @@ void intel_ddi_init(struct drm_device *dev, > > > enum port port) > > > intel_dig_port->port = port; > > > intel_dig_port->saved_port_bits = > > > I915_READ(DDI_BUF_CTL(port)) & > > > (DDI_BUF_PORT_REVERSAL | > > > - DDI_A_4_LANES); > > > + ddi_e_present ? 0 : > > > DDI_A_4_LANES); > > [Zhang, Xiong Y] Sonika's patch will set DDI-A to 4 lanes when DDI-E > > doesn't exist, I think your patch will do nothing. > > Actually DDI_A_4_LANES is being already set unconditionally, so Sonika's > patch has no effect. [Zhang, Xiong Y] No. Sonika's patch set DDI_A_4_LANES under many conditions. + if (IS_SKYLAKE(dev) && port == PORT_A + && !(val & DDI_BUF_CTL_ENABLE) + && !dev_priv->vbt.ddi_e_used) + I915_WRITE(DDI_BUF_CTL(port), val | DDI_A_4_LANES) > > saved_port_bits goes to intel_dp->DP that goes to DDI_BUF_CTL and also it is > used to calculate the number of lanes. > > With this patch we stop setting DDI_A_4_LANES when ddi_e is present so > DDI-A keeps with 2 lanes and let other 2 lanes for DDI-E [Zhang, Xiong Y] Yes, this patch will clear DDI_A_4_LANES when ddi_e is present. But this patch won't set DDI_A_4_LANES under following conditions which is purpose for Sonika patch 1. Bios fail to driver eDP and doesn't enable DDI_A buffer 2. Bios clear DDI_A_4_LANES 3. DDI_E isn't present
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