Re: [PATCH 20/24] drm/i915/icl: implement the tc/legacy HPD {dis, }connect flow for DP

[Paulo Zanoni <paulo.r.zanoni@intel.com>]

Em Qui, 2018-06-21 às 15:04 -0700, Srivatsa, Anusha escreveu:
> > -----Original Message-----
> > From: Intel-gfx [mailto:intel-gfx-bounces@lists.freedesktop.org] On
> > Behalf Of
> > Paulo Zanoni
> > Sent: Monday, May 21, 2018 5:26 PM
> > To: intel-gfx@lists.freedesktop.org
> > Cc: Zanoni, Paulo R <paulo.r.zanoni@intel.com>
> > Subject: [Intel-gfx] [PATCH 20/24] drm/i915/icl: implement the
> > tc/legacy HPD
> > {dis, }connect flow for DP
> > 
> > Implement the DFLEXDPPMS/DFLEXDPCSSS dance for DisplayPort. These
> > functions need to be called during HPD assert/deassert, but due to
> > how our driver
> > works it's much simpler if we always call them when
> > icl_digital_port_connected() is called, which means we won't call
> > them exactly
> > once per HPD event. This should also cover the connected boot case,
> > whatever
> > the BIOS does.
> > 
> > We're still missing the HDMI case, which should be implemented in
> > the next
> > patch.
> > 
> > Also notice that, today, the BSpec pages for the DFLEXDPPMS and
> > DFLEXDPCSSS
> > registers are wrong, so you should only trust the flows described
> > by the "Gen11
> > TypeC Programming" page in our spec.
> > 
> > Cc: Animesh Manna <animesh.manna@intel.com>
> > Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
> > ---
> > drivers/gpu/drm/i915/i915_reg.h |  6
> > +++++  drivers/gpu/drm/i915/intel_dp.c |
> > 57 ++++++++++++++++++++++++++++++++++++++++-
> > 2 files changed, 62 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h
> > b/drivers/gpu/drm/i915/i915_reg.h
> > index 24308d4435f5..42cbace4c61e 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -10027,4 +10027,10 @@ enum skl_power_gate {
> > 						 _ICL_PHY_MISC_B)
> > #define  ICL_PHY_MISC_DE_IO_COMP_PWR_DOWN	(1 << 23)
> > 
> > +#define PORT_TX_DFLEXDPPMS
> > 	_MMIO(0x163890)
> > +#define   DP_PHY_MODE_STATUS_COMPLETED(tc_port)		(1
> > <<
> > (tc_port))
> > +
> > +#define PORT_TX_DFLEXDPCSSS
> > 	_MMIO(0x163894)
> > +#define   DP_PHY_MODE_STATUS_NOT_SAFE(tc_port)		(1
> > << (tc_port))
> > +
> > #endif /* _I915_REG_H_ */
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c
> > b/drivers/gpu/drm/i915/intel_dp.c
> > index f3d5b9eed625..f25f871e7c22 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -4762,6 +4762,56 @@ static void icl_update_tc_port_type(struct
> > drm_i915_private *dev_priv,
> > 			      type_str);
> > }
> > 
> > +static bool icl_tc_phy_mode_status_connect(struct drm_i915_private
> > *dev_priv,
> > +					   struct
> > intel_digital_port *dig_port) {
> > +	enum tc_port tc_port = intel_port_to_tc(dev_priv,
> > dig_port->base.port);
> > +	u32 val;
> > +
> > +	if (dig_port->tc_type != TC_PORT_LEGACY &&
> > +	    dig_port->tc_type != TC_PORT_TYPEC)
> > +		return true;
> 
> 		Shouldn’t this return false?

Types that don't need to run this sequence can be considered connected,
so we return true.


> 
> > +	val = I915_READ(PORT_TX_DFLEXDPPMS);
> > +	if (!(val & DP_PHY_MODE_STATUS_COMPLETED(tc_port))) {
> > +		DRM_ERROR("DP PHY for TC port %d not ready\n",
> > tc_port);
> > +		return false;
> > +	}
> > +
> > +	/*
> > +	 * This function may be called many times in a row without
> > an HPD event
> > +	 * in between, so try to avoid the write when we can.
> > +	 */
> > +	val = I915_READ(PORT_TX_DFLEXDPCSSS);
> > +	if (!(val & DP_PHY_MODE_STATUS_NOT_SAFE(tc_port))) {
> > +		val |= DP_PHY_MODE_STATUS_NOT_SAFE(tc_port);
> > +		I915_WRITE(PORT_TX_DFLEXDPCSSS, val);
> > +	}
> > +
> > +	return true;
> > +}
> > +
> > +static void icl_tc_phy_mode_status_disconnect(struct
> > drm_i915_private
> > *dev_priv,
> > +					      struct
> > intel_digital_port *dig_port) {
> > +	enum tc_port tc_port = intel_port_to_tc(dev_priv,
> > dig_port->base.port);
> > +	u32 val;
> > +
> > +	if (dig_port->tc_type != TC_PORT_LEGACY &&
> > +	    dig_port->tc_type != TC_PORT_TYPEC)
> > +		return;
> > +
> > +	/*
> > +	 * This function may be called many times in a row without
> > an HPD event
> > +	 * in between, so try to avoid the write when we can.
> > +	 */
> 
> So, in the sequences to enable, it does tell that enabling suitable
> aux power domains is optional. But in the disable sequence, disable
> AUX_PWR is mentioned as a non-optional step. 
> In which case it has to be before we set DFLEXDPCSSS register to 0.
> 
>  Is it being addressed in another patch?

It should be disabled here because we're not using the port anymore at
this point.

> 
> The rest of the patch looks good.
> 
> Anusha 
> 
> > +	val = I915_READ(PORT_TX_DFLEXDPCSSS);
> > +	if (val & DP_PHY_MODE_STATUS_NOT_SAFE(tc_port)) {
> > +		val &= ~DP_PHY_MODE_STATUS_NOT_SAFE(tc_port);
> > +		I915_WRITE(PORT_TX_DFLEXDPCSSS, val);
> > +	}
> > +}
> > +
> > static bool icl_tc_port_connected(struct drm_i915_private
> > *dev_priv,
> > 				  struct intel_digital_port
> > *intel_dig_port)  { @@
> > -4782,12 +4832,17 @@ static bool icl_tc_port_connected(struct
> > drm_i915_private *dev_priv,
> > 	if (cpu_isr & tbt_bit)
> > 		is_tbt = true;
> > 
> > -	if (!is_legacy && !is_typec && !is_tbt)
> > +	if (!is_legacy && !is_typec && !is_tbt) {
> > +		icl_tc_phy_mode_status_disconnect(dev_priv,
> > intel_dig_port);
> > 		return false;
> > +	}
> > 
> > 	icl_update_tc_port_type(dev_priv, intel_dig_port, is_legacy,
> > is_typec,
> > 				is_tbt);
> > 
> > +	if (!icl_tc_phy_mode_status_connect(dev_priv,
> > intel_dig_port))
> > +		return false;
> > +
> > 	return true;
> > }
> > 
> > --
> > 2.14.3
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
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