[5/6] drm/i915/tc/icl: Implement TC cold sequences
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Message ID 20200401004120.408586-5-jose.souza@intel.com
State New
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Series
  • [1/6] drm/i915/display: Move out code to return the digital_port of the aux ch
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Commit Message

Souza, Jose April 1, 2020, 12:41 a.m. UTC
This is required for legacy/static TC ports as IOM is not aware of
the connection and will not trigger the TC cold exit.

Just request PCODE to exit TCCOLD is not enough as it could enter
again be driver makes use of the port, to prevent it BSpec states that
aux powerwell should be held.

So here embedding the TC cold exit sequence into ICL aux enable,
it will enable aux, request tc cold exit and depending in the TC live
state continue with the regular aux enable sequence.

And then turning on aux power well during tc lock and turning off
during unlock both depending into the TC port refcount.

BSpec: 21750
Fixes: https://gitlab.freedesktop.org/drm/intel/issues/1296
Cc: Imre Deak <imre.deak@intel.com>
Cc: Cooper Chiou <cooper.chiou@intel.com>
Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
---

Will run some tests in the office with TBT dockstation to check if
it will be a issue keep both aux enabled. Otherwise more changes will
be required here.

 .../drm/i915/display/intel_display_power.c    | 12 ++++-
 .../drm/i915/display/intel_display_types.h    |  1 +
 drivers/gpu/drm/i915/display/intel_tc.c       | 47 ++++++++++++++++++-
 drivers/gpu/drm/i915/display/intel_tc.h       |  2 +
 drivers/gpu/drm/i915/i915_reg.h               |  1 +
 5 files changed, 59 insertions(+), 4 deletions(-)

Comments

Imre Deak April 1, 2020, 12:43 p.m. UTC | #1
On Tue, Mar 31, 2020 at 05:41:19PM -0700, José Roberto de Souza wrote:
> This is required for legacy/static TC ports as IOM is not aware of
> the connection and will not trigger the TC cold exit.
> 
> Just request PCODE to exit TCCOLD is not enough as it could enter
> again be driver makes use of the port, to prevent it BSpec states that
> aux powerwell should be held.
> 
> So here embedding the TC cold exit sequence into ICL aux enable,
> it will enable aux, request tc cold exit and depending in the TC live
> state continue with the regular aux enable sequence.
> 
> And then turning on aux power well during tc lock and turning off
> during unlock both depending into the TC port refcount.
> 
> BSpec: 21750
> Fixes: https://gitlab.freedesktop.org/drm/intel/issues/1296
> Cc: Imre Deak <imre.deak@intel.com>
> Cc: Cooper Chiou <cooper.chiou@intel.com>
> Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
> Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
> ---
> 
> Will run some tests in the office with TBT dockstation to check if
> it will be a issue keep both aux enabled. Otherwise more changes will
> be required here.
> 
>  .../drm/i915/display/intel_display_power.c    | 12 ++++-
>  .../drm/i915/display/intel_display_types.h    |  1 +
>  drivers/gpu/drm/i915/display/intel_tc.c       | 47 ++++++++++++++++++-
>  drivers/gpu/drm/i915/display/intel_tc.h       |  2 +
>  drivers/gpu/drm/i915/i915_reg.h               |  1 +
>  5 files changed, 59 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c
> index dbd61517ba63..1ccd57d645c7 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_power.c
> @@ -592,9 +592,17 @@ icl_tc_phy_aux_power_well_enable(struct drm_i915_private *dev_priv,
>  
>  	_hsw_power_well_enable(dev_priv, power_well);
>  
> -	/* TODO ICL TC cold handling */
> +	if (INTEL_GEN(dev_priv) == 11)

Should be if (ICL && dig_port->tc_legacy_port)

> +		intel_tc_icl_tc_cold_exit(dev_priv);
>  
> -	_hsw_power_well_continue_enable(dev_priv, power_well);
> +	/*
> +	 * To avoid power well enable timeouts when disconnected or in TBT mode
> +	 * when doing the TC cold exit sequence for GEN11
> +	 */
> +	if (INTEL_GEN(dev_priv) != 11 ||
> +	    (intel_tc_port_live_status_mask(dig_port) &
> +	     (TC_PORT_LEGACY | TC_PORT_DP_ALT)))
> +		_hsw_power_well_continue_enable(dev_priv, power_well);

Why can't we call this unconditionally?

>  
>  	if (INTEL_GEN(dev_priv) >= 12 && !power_well->desc->hsw.is_tc_tbt) {
>  		enum tc_port tc_port;
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 176ab5f1e867..a9a4a3c1b4d7 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -1391,6 +1391,7 @@ struct intel_digital_port {
>  	enum intel_display_power_domain ddi_io_power_domain;
>  	struct mutex tc_lock;	/* protects the TypeC port mode */
>  	intel_wakeref_t tc_lock_wakeref;
> +	intel_wakeref_t tc_cold_wakeref;
>  	int tc_link_refcount;
>  	bool tc_legacy_port:1;
>  	char tc_port_name[8];
> diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
> index d944be935423..b6d67f069ef7 100644
> --- a/drivers/gpu/drm/i915/display/intel_tc.c
> +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> @@ -7,6 +7,7 @@
>  #include "intel_display.h"
>  #include "intel_display_types.h"
>  #include "intel_dp_mst.h"
> +#include "intel_sideband.h"
>  #include "intel_tc.h"
>  
>  static const char *tc_port_mode_name(enum tc_port_mode mode)
> @@ -506,6 +507,13 @@ static void __intel_tc_port_lock(struct intel_digital_port *dig_port,
>  
>  	mutex_lock(&dig_port->tc_lock);
>  
> +	if (INTEL_GEN(i915) == 11 && dig_port->tc_link_refcount == 0) {
> +		enum intel_display_power_domain aux_domain;
> +
> +		aux_domain = intel_aux_ch_to_power_domain(dig_port->aux_ch);
> +		dig_port->tc_cold_wakeref = intel_display_power_get(i915, aux_domain);
> +	}
> +

It would be enough to hold this ref only for the time we access FIA
regs. Anything else later will hold its own AUX reference, which takes
care of blocking tc-cold. So here something like:

	tc_cold_wakeref = block_tc_cold(dig_port);

where block_tc_cold() would return a non-NULL wakeref only for
ICL/dig_port->tc_legacy_port and TGL.

>  	if (!dig_port->tc_link_refcount &&
>  	    intel_tc_port_needs_reset(dig_port))
>  		intel_tc_port_reset_mode(dig_port, required_lanes);

	unblock_tc_cold(tc_cold_wakeref);

We need to call block/unblock_tc_cold() also in intel_tc_port_sanitize()
and intel_tc_port_connected().

> @@ -519,15 +527,30 @@ void intel_tc_port_lock(struct intel_digital_port *dig_port)
>  	__intel_tc_port_lock(dig_port, 1);
>  }
>  
> +static void icl_tc_cold_unblock(struct intel_digital_port *dig_port)
> +{
> +	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> +	enum intel_display_power_domain aux_domain;
> +	intel_wakeref_t tc_cold_wakeref;
> +
> +	if (INTEL_GEN(i915) != 11 || dig_port->tc_link_refcount > 0)
> +		return;
> +
> +	tc_cold_wakeref = fetch_and_zero(&dig_port->tc_cold_wakeref);
> +	aux_domain = intel_aux_ch_to_power_domain(dig_port->aux_ch);
> +	intel_display_power_put_async(i915, aux_domain, tc_cold_wakeref);
> +}
> +
>  void intel_tc_port_unlock(struct intel_digital_port *dig_port)
>  {
>  	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
>  	intel_wakeref_t wakeref = fetch_and_zero(&dig_port->tc_lock_wakeref);
>  
> +	icl_tc_cold_unblock(dig_port);
> +
>  	mutex_unlock(&dig_port->tc_lock);
>  
> -	intel_display_power_put_async(i915, POWER_DOMAIN_DISPLAY_CORE,
> -				      wakeref);
> +	intel_display_power_put_async(i915, POWER_DOMAIN_DISPLAY_CORE, wakeref);
>  }
>  
>  bool intel_tc_port_ref_held(struct intel_digital_port *dig_port)
> @@ -548,6 +571,7 @@ void intel_tc_port_put_link(struct intel_digital_port *dig_port)
>  {
>  	mutex_lock(&dig_port->tc_lock);
>  	dig_port->tc_link_refcount--;
> +	icl_tc_cold_unblock(dig_port);
>  	mutex_unlock(&dig_port->tc_lock);
>  }
>  
> @@ -568,3 +592,22 @@ void intel_tc_port_init(struct intel_digital_port *dig_port, bool is_legacy)
>  	dig_port->tc_link_refcount = 0;
>  	tc_port_load_fia_params(i915, dig_port);
>  }
> +
> +void intel_tc_icl_tc_cold_exit(struct drm_i915_private *i915)

This could be in intel_display_power.c now, so we don't need to export
it.

> +{
> +	int ret;
> +
> +	do {
> +		ret = sandybridge_pcode_write_timeout(i915,
> +						      ICL_PCODE_EXIT_TCCOLD,
> +						      0, 250, 1);
> +
> +	} while (ret == -EAGAIN);
> +
> +	if (!ret)
> +		msleep(1);

Could you add a comment explaining that we need the sleep, since
according to BSpec the above request may not have completed even though
it returned success?

> +
> +	if (ret)
> +		drm_dbg_kms(&i915->drm, "TC cold block %s\n",
> +			    (ret == 0 ? "succeeded" : "failed"));
> +}
> diff --git a/drivers/gpu/drm/i915/display/intel_tc.h b/drivers/gpu/drm/i915/display/intel_tc.h
> index a1afcee48818..168d8896fcfd 100644
> --- a/drivers/gpu/drm/i915/display/intel_tc.h
> +++ b/drivers/gpu/drm/i915/display/intel_tc.h
> @@ -9,6 +9,7 @@
>  #include <linux/mutex.h>
>  #include <linux/types.h>
>  
> +struct drm_i915_private;
>  struct intel_digital_port;
>  
>  bool intel_tc_port_connected(struct intel_digital_port *dig_port);
> @@ -29,5 +30,6 @@ bool intel_tc_port_ref_held(struct intel_digital_port *dig_port);
>  void intel_tc_port_init(struct intel_digital_port *dig_port, bool is_legacy);
>  
>  u32 intel_tc_port_live_status_mask(struct intel_digital_port *dig_port);
> +void intel_tc_icl_tc_cold_exit(struct drm_i915_private *i915);
>  
>  #endif /* __INTEL_TC_H__ */
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 17484345cb80..b111815d6596 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -9107,6 +9107,7 @@ enum {
>  #define     ICL_PCODE_MEM_SS_READ_QGV_POINT_INFO(point)	(((point) << 16) | (0x1 << 8))
>  #define   GEN6_PCODE_READ_D_COMP		0x10
>  #define   GEN6_PCODE_WRITE_D_COMP		0x11
> +#define   ICL_PCODE_EXIT_TCCOLD			0x12
>  #define   HSW_PCODE_DE_WRITE_FREQ_REQ		0x17
>  #define   DISPLAY_IPS_CONTROL			0x19
>              /* See also IPS_CTL */
> -- 
> 2.26.0
>
Souza, Jose April 1, 2020, 10:35 p.m. UTC | #2
On Wed, 2020-04-01 at 15:43 +0300, Imre Deak wrote:
> On Tue, Mar 31, 2020 at 05:41:19PM -0700, José Roberto de Souza
> wrote:
> > This is required for legacy/static TC ports as IOM is not aware of
> > the connection and will not trigger the TC cold exit.
> > 
> > Just request PCODE to exit TCCOLD is not enough as it could enter
> > again be driver makes use of the port, to prevent it BSpec states
> > that
> > aux powerwell should be held.
> > 
> > So here embedding the TC cold exit sequence into ICL aux enable,
> > it will enable aux, request tc cold exit and depending in the TC
> > live
> > state continue with the regular aux enable sequence.
> > 
> > And then turning on aux power well during tc lock and turning off
> > during unlock both depending into the TC port refcount.
> > 
> > BSpec: 21750
> > Fixes: https://gitlab.freedesktop.org/drm/intel/issues/1296
> > Cc: Imre Deak <imre.deak@intel.com>
> > Cc: Cooper Chiou <cooper.chiou@intel.com>
> > Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
> > Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
> > ---
> > 
> > Will run some tests in the office with TBT dockstation to check if
> > it will be a issue keep both aux enabled. Otherwise more changes
> > will
> > be required here.
> > 
> >  .../drm/i915/display/intel_display_power.c    | 12 ++++-
> >  .../drm/i915/display/intel_display_types.h    |  1 +
> >  drivers/gpu/drm/i915/display/intel_tc.c       | 47
> > ++++++++++++++++++-
> >  drivers/gpu/drm/i915/display/intel_tc.h       |  2 +
> >  drivers/gpu/drm/i915/i915_reg.h               |  1 +
> >  5 files changed, 59 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c
> > b/drivers/gpu/drm/i915/display/intel_display_power.c
> > index dbd61517ba63..1ccd57d645c7 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_power.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display_power.c
> > @@ -592,9 +592,17 @@ icl_tc_phy_aux_power_well_enable(struct
> > drm_i915_private *dev_priv,
> >  
> >  	_hsw_power_well_enable(dev_priv, power_well);
> >  
> > -	/* TODO ICL TC cold handling */
> > +	if (INTEL_GEN(dev_priv) == 11)
> 
> Should be if (ICL && dig_port->tc_legacy_port)

Makes sence.
Oh so we could use it on __intel_tc_port_lock() too and
don't do this stuff for non legacy ports. Until we get a report of a
system with a wrong VBT :P

> 
> > +		intel_tc_icl_tc_cold_exit(dev_priv);
> >  
> > -	_hsw_power_well_continue_enable(dev_priv, power_well);
> > +	/*
> > +	 * To avoid power well enable timeouts when disconnected or in
> > TBT mode
> > +	 * when doing the TC cold exit sequence for GEN11
> > +	 */
> > +	if (INTEL_GEN(dev_priv) != 11 ||
> > +	    (intel_tc_port_live_status_mask(dig_port) &
> > +	     (TC_PORT_LEGACY | TC_PORT_DP_ALT)))
> > +		_hsw_power_well_continue_enable(dev_priv, power_well);
> 
> Why can't we call this unconditionally?

Because we are requesting aux power of regular TC ports as part of tc
cold exit sequence, if the port is disconnected it will timeout in
hsw_wait_for_power_well_enable().

Anyways it is wrong as it is not
taking care of TBT ports, so changing to: if (INTEL_GEN(dev_priv) != 11
|| !dig_port->tc_legacy_port || intel_tc_port_live_status_mask())

> 
> >  
> >  	if (INTEL_GEN(dev_priv) >= 12 && !power_well->desc-
> > >hsw.is_tc_tbt) {
> >  		enum tc_port tc_port;
> > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > index 176ab5f1e867..a9a4a3c1b4d7 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > @@ -1391,6 +1391,7 @@ struct intel_digital_port {
> >  	enum intel_display_power_domain ddi_io_power_domain;
> >  	struct mutex tc_lock;	/* protects the TypeC port mode */
> >  	intel_wakeref_t tc_lock_wakeref;
> > +	intel_wakeref_t tc_cold_wakeref;
> >  	int tc_link_refcount;
> >  	bool tc_legacy_port:1;
> >  	char tc_port_name[8];
> > diff --git a/drivers/gpu/drm/i915/display/intel_tc.c
> > b/drivers/gpu/drm/i915/display/intel_tc.c
> > index d944be935423..b6d67f069ef7 100644
> > --- a/drivers/gpu/drm/i915/display/intel_tc.c
> > +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> > @@ -7,6 +7,7 @@
> >  #include "intel_display.h"
> >  #include "intel_display_types.h"
> >  #include "intel_dp_mst.h"
> > +#include "intel_sideband.h"
> >  #include "intel_tc.h"
> >  
> >  static const char *tc_port_mode_name(enum tc_port_mode mode)
> > @@ -506,6 +507,13 @@ static void __intel_tc_port_lock(struct
> > intel_digital_port *dig_port,
> >  
> >  	mutex_lock(&dig_port->tc_lock);
> >  
> > +	if (INTEL_GEN(i915) == 11 && dig_port->tc_link_refcount == 0) {
> > +		enum intel_display_power_domain aux_domain;
> > +
> > +		aux_domain = intel_aux_ch_to_power_domain(dig_port-
> > >aux_ch);
> > +		dig_port->tc_cold_wakeref =
> > intel_display_power_get(i915, aux_domain);
> > +	}
> > +
> 
> It would be enough to hold this ref only for the time we access FIA
> regs. Anything else later will hold its own AUX reference, which
> takes
> care of blocking tc-cold. So here something like:
> 

According to BSpec we need to keep TC cold blocked while accessing TC
PHY registers too.

> 	tc_cold_wakeref = block_tc_cold(dig_port);
> 
> where block_tc_cold() would return a non-NULL wakeref only for
> ICL/dig_port->tc_legacy_port and TGL.
> 
> >  	if (!dig_port->tc_link_refcount &&
> >  	    intel_tc_port_needs_reset(dig_port))
> >  		intel_tc_port_reset_mode(dig_port, required_lanes);
> 
> 	unblock_tc_cold(tc_cold_wakeref);
> 
> We need to call block/unblock_tc_cold() also in
> intel_tc_port_sanitize()
> and intel_tc_port_connected().
> 
> > @@ -519,15 +527,30 @@ void intel_tc_port_lock(struct
> > intel_digital_port *dig_port)
> >  	__intel_tc_port_lock(dig_port, 1);
> >  }
> >  
> > +static void icl_tc_cold_unblock(struct intel_digital_port
> > *dig_port)
> > +{
> > +	struct drm_i915_private *i915 = to_i915(dig_port-
> > >base.base.dev);
> > +	enum intel_display_power_domain aux_domain;
> > +	intel_wakeref_t tc_cold_wakeref;
> > +
> > +	if (INTEL_GEN(i915) != 11 || dig_port->tc_link_refcount > 0)
> > +		return;
> > +
> > +	tc_cold_wakeref = fetch_and_zero(&dig_port->tc_cold_wakeref);
> > +	aux_domain = intel_aux_ch_to_power_domain(dig_port->aux_ch);
> > +	intel_display_power_put_async(i915, aux_domain,
> > tc_cold_wakeref);
> > +}
> > +
> >  void intel_tc_port_unlock(struct intel_digital_port *dig_port)
> >  {
> >  	struct drm_i915_private *i915 = to_i915(dig_port-
> > >base.base.dev);
> >  	intel_wakeref_t wakeref = fetch_and_zero(&dig_port-
> > >tc_lock_wakeref);
> >  
> > +	icl_tc_cold_unblock(dig_port);
> > +
> >  	mutex_unlock(&dig_port->tc_lock);
> >  
> > -	intel_display_power_put_async(i915, POWER_DOMAIN_DISPLAY_CORE,
> > -				      wakeref);
> > +	intel_display_power_put_async(i915, POWER_DOMAIN_DISPLAY_CORE,
> > wakeref);
> >  }
> >  
> >  bool intel_tc_port_ref_held(struct intel_digital_port *dig_port)
> > @@ -548,6 +571,7 @@ void intel_tc_port_put_link(struct
> > intel_digital_port *dig_port)
> >  {
> >  	mutex_lock(&dig_port->tc_lock);
> >  	dig_port->tc_link_refcount--;
> > +	icl_tc_cold_unblock(dig_port);
> >  	mutex_unlock(&dig_port->tc_lock);
> >  }
> >  
> > @@ -568,3 +592,22 @@ void intel_tc_port_init(struct
> > intel_digital_port *dig_port, bool is_legacy)
> >  	dig_port->tc_link_refcount = 0;
> >  	tc_port_load_fia_params(i915, dig_port);
> >  }
> > +
> > +void intel_tc_icl_tc_cold_exit(struct drm_i915_private *i915)
> 
> This could be in intel_display_power.c now, so we don't need to
> export
> it.

Okay.

> 
> > +{
> > +	int ret;
> > +
> > +	do {
> > +		ret = sandybridge_pcode_write_timeout(i915,
> > +						      ICL_PCODE_EXIT_TC
> > COLD,
> > +						      0, 250, 1);
> > +
> > +	} while (ret == -EAGAIN);
> > +
> > +	if (!ret)
> > +		msleep(1);
> 
> Could you add a comment explaining that we need the sleep, since
> according to BSpec the above request may not have completed even
> though
> it returned success?

Sure

> 
> > +
> > +	if (ret)
> > +		drm_dbg_kms(&i915->drm, "TC cold block %s\n",
> > +			    (ret == 0 ? "succeeded" : "failed"));
> > +}
> > diff --git a/drivers/gpu/drm/i915/display/intel_tc.h
> > b/drivers/gpu/drm/i915/display/intel_tc.h
> > index a1afcee48818..168d8896fcfd 100644
> > --- a/drivers/gpu/drm/i915/display/intel_tc.h
> > +++ b/drivers/gpu/drm/i915/display/intel_tc.h
> > @@ -9,6 +9,7 @@
> >  #include <linux/mutex.h>
> >  #include <linux/types.h>
> >  
> > +struct drm_i915_private;
> >  struct intel_digital_port;
> >  
> >  bool intel_tc_port_connected(struct intel_digital_port *dig_port);
> > @@ -29,5 +30,6 @@ bool intel_tc_port_ref_held(struct
> > intel_digital_port *dig_port);
> >  void intel_tc_port_init(struct intel_digital_port *dig_port, bool
> > is_legacy);
> >  
> >  u32 intel_tc_port_live_status_mask(struct intel_digital_port
> > *dig_port);
> > +void intel_tc_icl_tc_cold_exit(struct drm_i915_private *i915);
> >  
> >  #endif /* __INTEL_TC_H__ */
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h
> > b/drivers/gpu/drm/i915/i915_reg.h
> > index 17484345cb80..b111815d6596 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -9107,6 +9107,7 @@ enum {
> >  #define     ICL_PCODE_MEM_SS_READ_QGV_POINT_INFO(point)	(((poin
> > t) << 16) | (0x1 << 8))
> >  #define   GEN6_PCODE_READ_D_COMP		0x10
> >  #define   GEN6_PCODE_WRITE_D_COMP		0x11
> > +#define   ICL_PCODE_EXIT_TCCOLD			0x12
> >  #define   HSW_PCODE_DE_WRITE_FREQ_REQ		0x17
> >  #define   DISPLAY_IPS_CONTROL			0x19
> >              /* See also IPS_CTL */
> > -- 
> > 2.26.0
> >
Imre Deak April 2, 2020, 1:02 a.m. UTC | #3
On Thu, Apr 02, 2020 at 01:35:30AM +0300, Souza, Jose wrote:
> On Wed, 2020-04-01 at 15:43 +0300, Imre Deak wrote:
> > On Tue, Mar 31, 2020 at 05:41:19PM -0700, José Roberto de Souza
> > wrote:
> > > This is required for legacy/static TC ports as IOM is not aware of
> > > the connection and will not trigger the TC cold exit.
> > > 
> > > Just request PCODE to exit TCCOLD is not enough as it could enter
> > > again be driver makes use of the port, to prevent it BSpec states
> > > that
> > > aux powerwell should be held.
> > > 
> > > So here embedding the TC cold exit sequence into ICL aux enable,
> > > it will enable aux, request tc cold exit and depending in the TC
> > > live
> > > state continue with the regular aux enable sequence.
> > > 
> > > And then turning on aux power well during tc lock and turning off
> > > during unlock both depending into the TC port refcount.
> > > 
> > > BSpec: 21750
> > > Fixes: https://gitlab.freedesktop.org/drm/intel/issues/1296
> > > Cc: Imre Deak <imre.deak@intel.com>
> > > Cc: Cooper Chiou <cooper.chiou@intel.com>
> > > Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
> > > Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
> > > ---
> > > 
> > > Will run some tests in the office with TBT dockstation to check if
> > > it will be a issue keep both aux enabled. Otherwise more changes
> > > will
> > > be required here.
> > > 
> > >  .../drm/i915/display/intel_display_power.c    | 12 ++++-
> > >  .../drm/i915/display/intel_display_types.h    |  1 +
> > >  drivers/gpu/drm/i915/display/intel_tc.c       | 47
> > > ++++++++++++++++++-
> > >  drivers/gpu/drm/i915/display/intel_tc.h       |  2 +
> > >  drivers/gpu/drm/i915/i915_reg.h               |  1 +
> > >  5 files changed, 59 insertions(+), 4 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c
> > > b/drivers/gpu/drm/i915/display/intel_display_power.c
> > > index dbd61517ba63..1ccd57d645c7 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display_power.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_display_power.c
> > > @@ -592,9 +592,17 @@ icl_tc_phy_aux_power_well_enable(struct
> > > drm_i915_private *dev_priv,
> > >  
> > >  	_hsw_power_well_enable(dev_priv, power_well);
> > >  
> > > -	/* TODO ICL TC cold handling */
> > > +	if (INTEL_GEN(dev_priv) == 11)
> > 
> > Should be if (ICL && dig_port->tc_legacy_port)
> 
> Makes sence.
> Oh so we could use it on __intel_tc_port_lock() too and
> don't do this stuff for non legacy ports. Until we get a report of a
> system with a wrong VBT :P

Yes, it's a loss of the vendor shipping a corrupt VBT. But we'll print
an error and fix up the flag.

> > > +		intel_tc_icl_tc_cold_exit(dev_priv);
> > >  
> > > -	_hsw_power_well_continue_enable(dev_priv, power_well);
> > > +	/*
> > > +	 * To avoid power well enable timeouts when disconnected or in
> > > TBT mode
> > > +	 * when doing the TC cold exit sequence for GEN11
> > > +	 */
> > > +	if (INTEL_GEN(dev_priv) != 11 ||
> > > +	    (intel_tc_port_live_status_mask(dig_port) &
> > > +	     (TC_PORT_LEGACY | TC_PORT_DP_ALT)))
> > > +		_hsw_power_well_continue_enable(dev_priv, power_well);
> > 
> > Why can't we call this unconditionally?
> 
> Because we are requesting aux power of regular TC ports as part of tc
> cold exit sequence, if the port is disconnected it will timeout in
> hsw_wait_for_power_well_enable().
> 
> Anyways it is wrong as it is not
> taking care of TBT ports, so changing to: if (INTEL_GEN(dev_priv) != 11
> || !dig_port->tc_legacy_port || intel_tc_port_live_status_mask())

What I thought is that the legacy AUX power request will ack after the
PCODE request completes, regardless of whether the sink is connected or
not. If that is not the case then let's just suppress the timeout for
legacy AUX power wells the same way we do that for TBT AUX. I don't like
to make the above call conditional on the live status flag, as that can
change at any moment. So in either case let's make the above call
unconditional.

> > >  
> > >  	if (INTEL_GEN(dev_priv) >= 12 && !power_well->desc-
> > > >hsw.is_tc_tbt) {

Could you check your email client, so that it doesn't wrap lines?

> > >  		enum tc_port tc_port;
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > index 176ab5f1e867..a9a4a3c1b4d7 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > @@ -1391,6 +1391,7 @@ struct intel_digital_port {
> > >  	enum intel_display_power_domain ddi_io_power_domain;
> > >  	struct mutex tc_lock;	/* protects the TypeC port mode */
> > >  	intel_wakeref_t tc_lock_wakeref;
> > > +	intel_wakeref_t tc_cold_wakeref;
> > >  	int tc_link_refcount;
> > >  	bool tc_legacy_port:1;
> > >  	char tc_port_name[8];
> > > diff --git a/drivers/gpu/drm/i915/display/intel_tc.c
> > > b/drivers/gpu/drm/i915/display/intel_tc.c
> > > index d944be935423..b6d67f069ef7 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_tc.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> > > @@ -7,6 +7,7 @@
> > >  #include "intel_display.h"
> > >  #include "intel_display_types.h"
> > >  #include "intel_dp_mst.h"
> > > +#include "intel_sideband.h"
> > >  #include "intel_tc.h"
> > >  
> > >  static const char *tc_port_mode_name(enum tc_port_mode mode)
> > > @@ -506,6 +507,13 @@ static void __intel_tc_port_lock(struct
> > > intel_digital_port *dig_port,
> > >  
> > >  	mutex_lock(&dig_port->tc_lock);
> > >  
> > > +	if (INTEL_GEN(i915) == 11 && dig_port->tc_link_refcount == 0) {
> > > +		enum intel_display_power_domain aux_domain;
> > > +
> > > +		aux_domain = intel_aux_ch_to_power_domain(dig_port-
> > > >aux_ch);
> > > +		dig_port->tc_cold_wakeref =
> > > intel_display_power_get(i915, aux_domain);
> > > +	}
> > > +
> > 
> > It would be enough to hold this ref only for the time we access FIA
> > regs. Anything else later will hold its own AUX reference, which
> > takes
> > care of blocking tc-cold. So here something like:
> > 
> 
> According to BSpec we need to keep TC cold blocked while accessing TC
> PHY registers too.

Yes, hence blocking it here whenever accessing the HW and elsewhere (AUX
transfers, modeset) whenever holding an AUX reference. See my comment
below about the other two functions in intel_tc that needs the
block/unblock.

> 
> > 	tc_cold_wakeref = block_tc_cold(dig_port);
> > 
> > where block_tc_cold() would return a non-NULL wakeref only for
> > ICL/dig_port->tc_legacy_port and TGL.
> > 
> > >  	if (!dig_port->tc_link_refcount &&
> > >  	    intel_tc_port_needs_reset(dig_port))
> > >  		intel_tc_port_reset_mode(dig_port, required_lanes);
> > 
> > 	unblock_tc_cold(tc_cold_wakeref);
> > 
> > We need to call block/unblock_tc_cold() also in
> > intel_tc_port_sanitize() and intel_tc_port_connected().
> > 
> > > @@ -519,15 +527,30 @@ void intel_tc_port_lock(struct
> > > intel_digital_port *dig_port)
> > >  	__intel_tc_port_lock(dig_port, 1);
> > >  }
> > >  
> > > +static void icl_tc_cold_unblock(struct intel_digital_port
> > > *dig_port)
> > > +{
> > > +	struct drm_i915_private *i915 = to_i915(dig_port-
> > > >base.base.dev);
> > > +	enum intel_display_power_domain aux_domain;
> > > +	intel_wakeref_t tc_cold_wakeref;
> > > +
> > > +	if (INTEL_GEN(i915) != 11 || dig_port->tc_link_refcount > 0)
> > > +		return;
> > > +
> > > +	tc_cold_wakeref = fetch_and_zero(&dig_port->tc_cold_wakeref);
> > > +	aux_domain = intel_aux_ch_to_power_domain(dig_port->aux_ch);
> > > +	intel_display_power_put_async(i915, aux_domain,
> > > tc_cold_wakeref);
> > > +}
> > > +
> > >  void intel_tc_port_unlock(struct intel_digital_port *dig_port)
> > >  {
> > >  	struct drm_i915_private *i915 = to_i915(dig_port-
> > > >base.base.dev);
> > >  	intel_wakeref_t wakeref = fetch_and_zero(&dig_port-
> > > >tc_lock_wakeref);
> > >  
> > > +	icl_tc_cold_unblock(dig_port);
> > > +
> > >  	mutex_unlock(&dig_port->tc_lock);
> > >  
> > > -	intel_display_power_put_async(i915, POWER_DOMAIN_DISPLAY_CORE,
> > > -				      wakeref);
> > > +	intel_display_power_put_async(i915, POWER_DOMAIN_DISPLAY_CORE,
> > > wakeref);
> > >  }
> > >  
> > >  bool intel_tc_port_ref_held(struct intel_digital_port *dig_port)
> > > @@ -548,6 +571,7 @@ void intel_tc_port_put_link(struct
> > > intel_digital_port *dig_port)
> > >  {
> > >  	mutex_lock(&dig_port->tc_lock);
> > >  	dig_port->tc_link_refcount--;
> > > +	icl_tc_cold_unblock(dig_port);
> > >  	mutex_unlock(&dig_port->tc_lock);
> > >  }
> > >  
> > > @@ -568,3 +592,22 @@ void intel_tc_port_init(struct
> > > intel_digital_port *dig_port, bool is_legacy)
> > >  	dig_port->tc_link_refcount = 0;
> > >  	tc_port_load_fia_params(i915, dig_port);
> > >  }
> > > +
> > > +void intel_tc_icl_tc_cold_exit(struct drm_i915_private *i915)
> > 
> > This could be in intel_display_power.c now, so we don't need to
> > export
> > it.
> 
> Okay.
> 
> > 
> > > +{
> > > +	int ret;
> > > +
> > > +	do {
> > > +		ret = sandybridge_pcode_write_timeout(i915,
> > > +						      ICL_PCODE_EXIT_TC
> > > COLD,
> > > +						      0, 250, 1);
> > > +
> > > +	} while (ret == -EAGAIN);
> > > +
> > > +	if (!ret)
> > > +		msleep(1);
> > 
> > Could you add a comment explaining that we need the sleep, since
> > according to BSpec the above request may not have completed even
> > though
> > it returned success?
> 
> Sure
> 
> > 
> > > +
> > > +	if (ret)
> > > +		drm_dbg_kms(&i915->drm, "TC cold block %s\n",
> > > +			    (ret == 0 ? "succeeded" : "failed"));
> > > +}
> > > diff --git a/drivers/gpu/drm/i915/display/intel_tc.h
> > > b/drivers/gpu/drm/i915/display/intel_tc.h
> > > index a1afcee48818..168d8896fcfd 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_tc.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_tc.h
> > > @@ -9,6 +9,7 @@
> > >  #include <linux/mutex.h>
> > >  #include <linux/types.h>
> > >  
> > > +struct drm_i915_private;
> > >  struct intel_digital_port;
> > >  
> > >  bool intel_tc_port_connected(struct intel_digital_port *dig_port);
> > > @@ -29,5 +30,6 @@ bool intel_tc_port_ref_held(struct
> > > intel_digital_port *dig_port);
> > >  void intel_tc_port_init(struct intel_digital_port *dig_port, bool
> > > is_legacy);
> > >  
> > >  u32 intel_tc_port_live_status_mask(struct intel_digital_port
> > > *dig_port);
> > > +void intel_tc_icl_tc_cold_exit(struct drm_i915_private *i915);
> > >  
> > >  #endif /* __INTEL_TC_H__ */
> > > diff --git a/drivers/gpu/drm/i915/i915_reg.h
> > > b/drivers/gpu/drm/i915/i915_reg.h
> > > index 17484345cb80..b111815d6596 100644
> > > --- a/drivers/gpu/drm/i915/i915_reg.h
> > > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > > @@ -9107,6 +9107,7 @@ enum {
> > >  #define     ICL_PCODE_MEM_SS_READ_QGV_POINT_INFO(point)	(((poin
> > > t) << 16) | (0x1 << 8))
> > >  #define   GEN6_PCODE_READ_D_COMP		0x10
> > >  #define   GEN6_PCODE_WRITE_D_COMP		0x11
> > > +#define   ICL_PCODE_EXIT_TCCOLD			0x12
> > >  #define   HSW_PCODE_DE_WRITE_FREQ_REQ		0x17
> > >  #define   DISPLAY_IPS_CONTROL			0x19
> > >              /* See also IPS_CTL */
> > > -- 
> > > 2.26.0
> > >
Souza, Jose April 3, 2020, 1:18 a.m. UTC | #4
Hi Imre

I guess I did all the requested changes but trybot got some
warnings that I will need more time to understand and fix it.

If you have time please check if is this way that you are asking:
https://github.com/zehortigoza/linux/tree/tccold-v3

Trybot warnings: 
https://intel-gfx-ci.01.org/tree/drm-tip/Trybot_5784/bat-all.html

Thanks

On Thu, 2020-04-02 at 04:02 +0300, Imre Deak wrote:
> On Thu, Apr 02, 2020 at 01:35:30AM +0300, Souza, Jose wrote:
> > On Wed, 2020-04-01 at 15:43 +0300, Imre Deak wrote:
> > > On Tue, Mar 31, 2020 at 05:41:19PM -0700, José Roberto de Souza
> > > wrote:
> > > > This is required for legacy/static TC ports as IOM is not aware
> > > > of
> > > > the connection and will not trigger the TC cold exit.
> > > > 
> > > > Just request PCODE to exit TCCOLD is not enough as it could
> > > > enter
> > > > again be driver makes use of the port, to prevent it BSpec
> > > > states
> > > > that
> > > > aux powerwell should be held.
> > > > 
> > > > So here embedding the TC cold exit sequence into ICL aux
> > > > enable,
> > > > it will enable aux, request tc cold exit and depending in the
> > > > TC
> > > > live
> > > > state continue with the regular aux enable sequence.
> > > > 
> > > > And then turning on aux power well during tc lock and turning
> > > > off
> > > > during unlock both depending into the TC port refcount.
> > > > 
> > > > BSpec: 21750
> > > > Fixes: https://gitlab.freedesktop.org/drm/intel/issues/1296
> > > > Cc: Imre Deak <imre.deak@intel.com>
> > > > Cc: Cooper Chiou <cooper.chiou@intel.com>
> > > > Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
> > > > Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
> > > > ---
> > > > 
> > > > Will run some tests in the office with TBT dockstation to check
> > > > if
> > > > it will be a issue keep both aux enabled. Otherwise more
> > > > changes
> > > > will
> > > > be required here.
> > > > 
> > > >  .../drm/i915/display/intel_display_power.c    | 12 ++++-
> > > >  .../drm/i915/display/intel_display_types.h    |  1 +
> > > >  drivers/gpu/drm/i915/display/intel_tc.c       | 47
> > > > ++++++++++++++++++-
> > > >  drivers/gpu/drm/i915/display/intel_tc.h       |  2 +
> > > >  drivers/gpu/drm/i915/i915_reg.h               |  1 +
> > > >  5 files changed, 59 insertions(+), 4 deletions(-)
> > > > 
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c
> > > > b/drivers/gpu/drm/i915/display/intel_display_power.c
> > > > index dbd61517ba63..1ccd57d645c7 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_display_power.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_display_power.c
> > > > @@ -592,9 +592,17 @@ icl_tc_phy_aux_power_well_enable(struct
> > > > drm_i915_private *dev_priv,
> > > >  
> > > >  	_hsw_power_well_enable(dev_priv, power_well);
> > > >  
> > > > -	/* TODO ICL TC cold handling */
> > > > +	if (INTEL_GEN(dev_priv) == 11)
> > > 
> > > Should be if (ICL && dig_port->tc_legacy_port)
> > 
> > Makes sence.
> > Oh so we could use it on __intel_tc_port_lock() too and
> > don't do this stuff for non legacy ports. Until we get a report of
> > a
> > system with a wrong VBT :P
> 
> Yes, it's a loss of the vendor shipping a corrupt VBT. But we'll
> print
> an error and fix up the flag.
> 
> > > > +		intel_tc_icl_tc_cold_exit(dev_priv);
> > > >  
> > > > -	_hsw_power_well_continue_enable(dev_priv, power_well);
> > > > +	/*
> > > > +	 * To avoid power well enable timeouts when
> > > > disconnected or in
> > > > TBT mode
> > > > +	 * when doing the TC cold exit sequence for GEN11
> > > > +	 */
> > > > +	if (INTEL_GEN(dev_priv) != 11 ||
> > > > +	    (intel_tc_port_live_status_mask(dig_port) &
> > > > +	     (TC_PORT_LEGACY | TC_PORT_DP_ALT)))
> > > > +		_hsw_power_well_continue_enable(dev_priv,
> > > > power_well);
> > > 
> > > Why can't we call this unconditionally?
> > 
> > Because we are requesting aux power of regular TC ports as part of
> > tc
> > cold exit sequence, if the port is disconnected it will timeout in
> > hsw_wait_for_power_well_enable().
> > 
> > Anyways it is wrong as it is not
> > taking care of TBT ports, so changing to: if (INTEL_GEN(dev_priv)
> > != 11
> > > > !dig_port->tc_legacy_port || intel_tc_port_live_status_mask())
> 
> What I thought is that the legacy AUX power request will ack after
> the
> PCODE request completes, regardless of whether the sink is connected
> or
> not. If that is not the case then let's just suppress the timeout for
> legacy AUX power wells the same way we do that for TBT AUX. I don't
> like
> to make the above call conditional on the live status flag, as that
> can
> change at any moment. So in either case let's make the above call
> unconditional.
> 
> > > >  
> > > >  	if (INTEL_GEN(dev_priv) >= 12 && !power_well->desc-
> > > > > hsw.is_tc_tbt) {
> 
> Could you check your email client, so that it doesn't wrap lines?
> 
> > > >  		enum tc_port tc_port;
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > index 176ab5f1e867..a9a4a3c1b4d7 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > @@ -1391,6 +1391,7 @@ struct intel_digital_port {
> > > >  	enum intel_display_power_domain ddi_io_power_domain;
> > > >  	struct mutex tc_lock;	/* protects the TypeC port mode
> > > > */
> > > >  	intel_wakeref_t tc_lock_wakeref;
> > > > +	intel_wakeref_t tc_cold_wakeref;
> > > >  	int tc_link_refcount;
> > > >  	bool tc_legacy_port:1;
> > > >  	char tc_port_name[8];
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_tc.c
> > > > b/drivers/gpu/drm/i915/display/intel_tc.c
> > > > index d944be935423..b6d67f069ef7 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_tc.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> > > > @@ -7,6 +7,7 @@
> > > >  #include "intel_display.h"
> > > >  #include "intel_display_types.h"
> > > >  #include "intel_dp_mst.h"
> > > > +#include "intel_sideband.h"
> > > >  #include "intel_tc.h"
> > > >  
> > > >  static const char *tc_port_mode_name(enum tc_port_mode mode)
> > > > @@ -506,6 +507,13 @@ static void __intel_tc_port_lock(struct
> > > > intel_digital_port *dig_port,
> > > >  
> > > >  	mutex_lock(&dig_port->tc_lock);
> > > >  
> > > > +	if (INTEL_GEN(i915) == 11 && dig_port->tc_link_refcount 
> > > > == 0) {
> > > > +		enum intel_display_power_domain aux_domain;
> > > > +
> > > > +		aux_domain =
> > > > intel_aux_ch_to_power_domain(dig_port-
> > > > > aux_ch);
> > > > +		dig_port->tc_cold_wakeref =
> > > > intel_display_power_get(i915, aux_domain);
> > > > +	}
> > > > +
> > > 
> > > It would be enough to hold this ref only for the time we access
> > > FIA
> > > regs. Anything else later will hold its own AUX reference, which
> > > takes
> > > care of blocking tc-cold. So here something like:
> > > 
> > 
> > According to BSpec we need to keep TC cold blocked while accessing
> > TC
> > PHY registers too.
> 
> Yes, hence blocking it here whenever accessing the HW and elsewhere
> (AUX
> transfers, modeset) whenever holding an AUX reference. See my comment
> below about the other two functions in intel_tc that needs the
> block/unblock.
> 
> > > 	tc_cold_wakeref = block_tc_cold(dig_port);
> > > 
> > > where block_tc_cold() would return a non-NULL wakeref only for
> > > ICL/dig_port->tc_legacy_port and TGL.
> > > 
> > > >  	if (!dig_port->tc_link_refcount &&
> > > >  	    intel_tc_port_needs_reset(dig_port))
> > > >  		intel_tc_port_reset_mode(dig_port,
> > > > required_lanes);
> > > 
> > > 	unblock_tc_cold(tc_cold_wakeref);
> > > 
> > > We need to call block/unblock_tc_cold() also in
> > > intel_tc_port_sanitize() and intel_tc_port_connected().
> > > 
> > > > @@ -519,15 +527,30 @@ void intel_tc_port_lock(struct
> > > > intel_digital_port *dig_port)
> > > >  	__intel_tc_port_lock(dig_port, 1);
> > > >  }
> > > >  
> > > > +static void icl_tc_cold_unblock(struct intel_digital_port
> > > > *dig_port)
> > > > +{
> > > > +	struct drm_i915_private *i915 = to_i915(dig_port-
> > > > > base.base.dev);
> > > > +	enum intel_display_power_domain aux_domain;
> > > > +	intel_wakeref_t tc_cold_wakeref;
> > > > +
> > > > +	if (INTEL_GEN(i915) != 11 || dig_port->tc_link_refcount 
> > > > > 0)
> > > > +		return;
> > > > +
> > > > +	tc_cold_wakeref = fetch_and_zero(&dig_port-
> > > > >tc_cold_wakeref);
> > > > +	aux_domain = intel_aux_ch_to_power_domain(dig_port-
> > > > >aux_ch);
> > > > +	intel_display_power_put_async(i915, aux_domain,
> > > > tc_cold_wakeref);
> > > > +}
> > > > +
> > > >  void intel_tc_port_unlock(struct intel_digital_port *dig_port)
> > > >  {
> > > >  	struct drm_i915_private *i915 = to_i915(dig_port-
> > > > > base.base.dev);
> > > >  	intel_wakeref_t wakeref = fetch_and_zero(&dig_port-
> > > > > tc_lock_wakeref);
> > > >  
> > > > +	icl_tc_cold_unblock(dig_port);
> > > > +
> > > >  	mutex_unlock(&dig_port->tc_lock);
> > > >  
> > > > -	intel_display_power_put_async(i915,
> > > > POWER_DOMAIN_DISPLAY_CORE,
> > > > -				      wakeref);
> > > > +	intel_display_power_put_async(i915,
> > > > POWER_DOMAIN_DISPLAY_CORE,
> > > > wakeref);
> > > >  }
> > > >  
> > > >  bool intel_tc_port_ref_held(struct intel_digital_port
> > > > *dig_port)
> > > > @@ -548,6 +571,7 @@ void intel_tc_port_put_link(struct
> > > > intel_digital_port *dig_port)
> > > >  {
> > > >  	mutex_lock(&dig_port->tc_lock);
> > > >  	dig_port->tc_link_refcount--;
> > > > +	icl_tc_cold_unblock(dig_port);
> > > >  	mutex_unlock(&dig_port->tc_lock);
> > > >  }
> > > >  
> > > > @@ -568,3 +592,22 @@ void intel_tc_port_init(struct
> > > > intel_digital_port *dig_port, bool is_legacy)
> > > >  	dig_port->tc_link_refcount = 0;
> > > >  	tc_port_load_fia_params(i915, dig_port);
> > > >  }
> > > > +
> > > > +void intel_tc_icl_tc_cold_exit(struct drm_i915_private *i915)
> > > 
> > > This could be in intel_display_power.c now, so we don't need to
> > > export
> > > it.
> > 
> > Okay.
> > 
> > > > +{
> > > > +	int ret;
> > > > +
> > > > +	do {
> > > > +		ret = sandybridge_pcode_write_timeout(i915,
> > > > +						      ICL_PCODE
> > > > _EXIT_TC
> > > > COLD,
> > > > +						      0, 250,
> > > > 1);
> > > > +
> > > > +	} while (ret == -EAGAIN);
> > > > +
> > > > +	if (!ret)
> > > > +		msleep(1);
> > > 
> > > Could you add a comment explaining that we need the sleep, since
> > > according to BSpec the above request may not have completed even
> > > though
> > > it returned success?
> > 
> > Sure
> > 
> > > > +
> > > > +	if (ret)
> > > > +		drm_dbg_kms(&i915->drm, "TC cold block %s\n",
> > > > +			    (ret == 0 ? "succeeded" :
> > > > "failed"));
> > > > +}
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_tc.h
> > > > b/drivers/gpu/drm/i915/display/intel_tc.h
> > > > index a1afcee48818..168d8896fcfd 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_tc.h
> > > > +++ b/drivers/gpu/drm/i915/display/intel_tc.h
> > > > @@ -9,6 +9,7 @@
> > > >  #include <linux/mutex.h>
> > > >  #include <linux/types.h>
> > > >  
> > > > +struct drm_i915_private;
> > > >  struct intel_digital_port;
> > > >  
> > > >  bool intel_tc_port_connected(struct intel_digital_port
> > > > *dig_port);
> > > > @@ -29,5 +30,6 @@ bool intel_tc_port_ref_held(struct
> > > > intel_digital_port *dig_port);
> > > >  void intel_tc_port_init(struct intel_digital_port *dig_port,
> > > > bool
> > > > is_legacy);
> > > >  
> > > >  u32 intel_tc_port_live_status_mask(struct intel_digital_port
> > > > *dig_port);
> > > > +void intel_tc_icl_tc_cold_exit(struct drm_i915_private *i915);
> > > >  
> > > >  #endif /* __INTEL_TC_H__ */
> > > > diff --git a/drivers/gpu/drm/i915/i915_reg.h
> > > > b/drivers/gpu/drm/i915/i915_reg.h
> > > > index 17484345cb80..b111815d6596 100644
> > > > --- a/drivers/gpu/drm/i915/i915_reg.h
> > > > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > > > @@ -9107,6 +9107,7 @@ enum {
> > > >  #define     ICL_PCODE_MEM_SS_READ_QGV_POINT_INFO(point)	
> > > > (((poin
> > > > t) << 16) | (0x1 << 8))
> > > >  #define   GEN6_PCODE_READ_D_COMP		0x10
> > > >  #define   GEN6_PCODE_WRITE_D_COMP		0x11
> > > > +#define   ICL_PCODE_EXIT_TCCOLD			0x12
> > > >  #define   HSW_PCODE_DE_WRITE_FREQ_REQ		0x17
> > > >  #define   DISPLAY_IPS_CONTROL			0x19
> > > >              /* See also IPS_CTL */
> > > > -- 
> > > > 2.26.0
> > > >
Imre Deak April 6, 2020, 12:57 p.m. UTC | #5
On Fri, Apr 03, 2020 at 04:18:54AM +0300, Souza, Jose wrote:
> Hi Imre
> 
> I guess I did all the requested changes but trybot got some
> warnings that I will need more time to understand and fix it.
> 
> If you have time please check if is this way that you are asking:
> https://github.com/zehortigoza/linux/tree/tccold-v3

Yes looks ok overall, I added a few comments on the trybot patches.

> Trybot warnings: 
> https://intel-gfx-ci.01.org/tree/drm-tip/Trybot_5784/bat-all.html

I see here
<3> [428.836598] [drm:tc_port_live_status_mask [i915]] *ERROR* Port D/TC#2: live status 00000004 mismatches the legacy port flag, fix flag

which is a known buggy VBT issue and

i915 0000:00:02.0: drm_WARN_ON(!power_well->desc->hsw.is_tc_tbt || !(((&(dev_priv)->__info)->gen) == 11 && dig_port->tc_legacy_port))

which is just a typo.

> Thanks
> 
> On Thu, 2020-04-02 at 04:02 +0300, Imre Deak wrote:
> > On Thu, Apr 02, 2020 at 01:35:30AM +0300, Souza, Jose wrote:
> > > On Wed, 2020-04-01 at 15:43 +0300, Imre Deak wrote:
> > > > On Tue, Mar 31, 2020 at 05:41:19PM -0700, José Roberto de Souza
> > > > wrote:
> > > > > This is required for legacy/static TC ports as IOM is not aware
> > > > > of
> > > > > the connection and will not trigger the TC cold exit.
> > > > > 
> > > > > Just request PCODE to exit TCCOLD is not enough as it could
> > > > > enter
> > > > > again be driver makes use of the port, to prevent it BSpec
> > > > > states
> > > > > that
> > > > > aux powerwell should be held.
> > > > > 
> > > > > So here embedding the TC cold exit sequence into ICL aux
> > > > > enable,
> > > > > it will enable aux, request tc cold exit and depending in the
> > > > > TC
> > > > > live
> > > > > state continue with the regular aux enable sequence.
> > > > > 
> > > > > And then turning on aux power well during tc lock and turning
> > > > > off
> > > > > during unlock both depending into the TC port refcount.
> > > > > 
> > > > > BSpec: 21750
> > > > > Fixes: https://gitlab.freedesktop.org/drm/intel/issues/1296
> > > > > Cc: Imre Deak <imre.deak@intel.com>
> > > > > Cc: Cooper Chiou <cooper.chiou@intel.com>
> > > > > Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
> > > > > Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
> > > > > ---
> > > > > 
> > > > > Will run some tests in the office with TBT dockstation to check
> > > > > if
> > > > > it will be a issue keep both aux enabled. Otherwise more
> > > > > changes
> > > > > will
> > > > > be required here.
> > > > > 
> > > > >  .../drm/i915/display/intel_display_power.c    | 12 ++++-
> > > > >  .../drm/i915/display/intel_display_types.h    |  1 +
> > > > >  drivers/gpu/drm/i915/display/intel_tc.c       | 47
> > > > > ++++++++++++++++++-
> > > > >  drivers/gpu/drm/i915/display/intel_tc.h       |  2 +
> > > > >  drivers/gpu/drm/i915/i915_reg.h               |  1 +
> > > > >  5 files changed, 59 insertions(+), 4 deletions(-)
> > > > > 
> > > > > diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c
> > > > > b/drivers/gpu/drm/i915/display/intel_display_power.c
> > > > > index dbd61517ba63..1ccd57d645c7 100644
> > > > > --- a/drivers/gpu/drm/i915/display/intel_display_power.c
> > > > > +++ b/drivers/gpu/drm/i915/display/intel_display_power.c
> > > > > @@ -592,9 +592,17 @@ icl_tc_phy_aux_power_well_enable(struct
> > > > > drm_i915_private *dev_priv,
> > > > >  
> > > > >  	_hsw_power_well_enable(dev_priv, power_well);
> > > > >  
> > > > > -	/* TODO ICL TC cold handling */
> > > > > +	if (INTEL_GEN(dev_priv) == 11)
> > > > 
> > > > Should be if (ICL && dig_port->tc_legacy_port)
> > > 
> > > Makes sence.
> > > Oh so we could use it on __intel_tc_port_lock() too and
> > > don't do this stuff for non legacy ports. Until we get a report of
> > > a
> > > system with a wrong VBT :P
> > 
> > Yes, it's a loss of the vendor shipping a corrupt VBT. But we'll
> > print
> > an error and fix up the flag.
> > 
> > > > > +		intel_tc_icl_tc_cold_exit(dev_priv);
> > > > >  
> > > > > -	_hsw_power_well_continue_enable(dev_priv, power_well);
> > > > > +	/*
> > > > > +	 * To avoid power well enable timeouts when
> > > > > disconnected or in
> > > > > TBT mode
> > > > > +	 * when doing the TC cold exit sequence for GEN11
> > > > > +	 */
> > > > > +	if (INTEL_GEN(dev_priv) != 11 ||
> > > > > +	    (intel_tc_port_live_status_mask(dig_port) &
> > > > > +	     (TC_PORT_LEGACY | TC_PORT_DP_ALT)))
> > > > > +		_hsw_power_well_continue_enable(dev_priv,
> > > > > power_well);
> > > > 
> > > > Why can't we call this unconditionally?
> > > 
> > > Because we are requesting aux power of regular TC ports as part of
> > > tc
> > > cold exit sequence, if the port is disconnected it will timeout in
> > > hsw_wait_for_power_well_enable().
> > > 
> > > Anyways it is wrong as it is not
> > > taking care of TBT ports, so changing to: if (INTEL_GEN(dev_priv)
> > > != 11
> > > > > !dig_port->tc_legacy_port || intel_tc_port_live_status_mask())
> > 
> > What I thought is that the legacy AUX power request will ack after
> > the
> > PCODE request completes, regardless of whether the sink is connected
> > or
> > not. If that is not the case then let's just suppress the timeout for
> > legacy AUX power wells the same way we do that for TBT AUX. I don't
> > like
> > to make the above call conditional on the live status flag, as that
> > can
> > change at any moment. So in either case let's make the above call
> > unconditional.
> > 
> > > > >  
> > > > >  	if (INTEL_GEN(dev_priv) >= 12 && !power_well->desc-
> > > > > > hsw.is_tc_tbt) {
> > 
> > Could you check your email client, so that it doesn't wrap lines?
> > 
> > > > >  		enum tc_port tc_port;
> > > > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > > index 176ab5f1e867..a9a4a3c1b4d7 100644
> > > > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > > @@ -1391,6 +1391,7 @@ struct intel_digital_port {
> > > > >  	enum intel_display_power_domain ddi_io_power_domain;
> > > > >  	struct mutex tc_lock;	/* protects the TypeC port mode
> > > > > */
> > > > >  	intel_wakeref_t tc_lock_wakeref;
> > > > > +	intel_wakeref_t tc_cold_wakeref;
> > > > >  	int tc_link_refcount;
> > > > >  	bool tc_legacy_port:1;
> > > > >  	char tc_port_name[8];
> > > > > diff --git a/drivers/gpu/drm/i915/display/intel_tc.c
> > > > > b/drivers/gpu/drm/i915/display/intel_tc.c
> > > > > index d944be935423..b6d67f069ef7 100644
> > > > > --- a/drivers/gpu/drm/i915/display/intel_tc.c
> > > > > +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> > > > > @@ -7,6 +7,7 @@
> > > > >  #include "intel_display.h"
> > > > >  #include "intel_display_types.h"
> > > > >  #include "intel_dp_mst.h"
> > > > > +#include "intel_sideband.h"
> > > > >  #include "intel_tc.h"
> > > > >  
> > > > >  static const char *tc_port_mode_name(enum tc_port_mode mode)
> > > > > @@ -506,6 +507,13 @@ static void __intel_tc_port_lock(struct
> > > > > intel_digital_port *dig_port,
> > > > >  
> > > > >  	mutex_lock(&dig_port->tc_lock);
> > > > >  
> > > > > +	if (INTEL_GEN(i915) == 11 && dig_port->tc_link_refcount 
> > > > > == 0) {
> > > > > +		enum intel_display_power_domain aux_domain;
> > > > > +
> > > > > +		aux_domain =
> > > > > intel_aux_ch_to_power_domain(dig_port-
> > > > > > aux_ch);
> > > > > +		dig_port->tc_cold_wakeref =
> > > > > intel_display_power_get(i915, aux_domain);
> > > > > +	}
> > > > > +
> > > > 
> > > > It would be enough to hold this ref only for the time we access
> > > > FIA
> > > > regs. Anything else later will hold its own AUX reference, which
> > > > takes
> > > > care of blocking tc-cold. So here something like:
> > > > 
> > > 
> > > According to BSpec we need to keep TC cold blocked while accessing
> > > TC
> > > PHY registers too.
> > 
> > Yes, hence blocking it here whenever accessing the HW and elsewhere
> > (AUX
> > transfers, modeset) whenever holding an AUX reference. See my comment
> > below about the other two functions in intel_tc that needs the
> > block/unblock.
> > 
> > > > 	tc_cold_wakeref = block_tc_cold(dig_port);
> > > > 
> > > > where block_tc_cold() would return a non-NULL wakeref only for
> > > > ICL/dig_port->tc_legacy_port and TGL.
> > > > 
> > > > >  	if (!dig_port->tc_link_refcount &&
> > > > >  	    intel_tc_port_needs_reset(dig_port))
> > > > >  		intel_tc_port_reset_mode(dig_port,
> > > > > required_lanes);
> > > > 
> > > > 	unblock_tc_cold(tc_cold_wakeref);
> > > > 
> > > > We need to call block/unblock_tc_cold() also in
> > > > intel_tc_port_sanitize() and intel_tc_port_connected().
> > > > 
> > > > > @@ -519,15 +527,30 @@ void intel_tc_port_lock(struct
> > > > > intel_digital_port *dig_port)
> > > > >  	__intel_tc_port_lock(dig_port, 1);
> > > > >  }
> > > > >  
> > > > > +static void icl_tc_cold_unblock(struct intel_digital_port
> > > > > *dig_port)
> > > > > +{
> > > > > +	struct drm_i915_private *i915 = to_i915(dig_port-
> > > > > > base.base.dev);
> > > > > +	enum intel_display_power_domain aux_domain;
> > > > > +	intel_wakeref_t tc_cold_wakeref;
> > > > > +
> > > > > +	if (INTEL_GEN(i915) != 11 || dig_port->tc_link_refcount 
> > > > > > 0)
> > > > > +		return;
> > > > > +
> > > > > +	tc_cold_wakeref = fetch_and_zero(&dig_port-
> > > > > >tc_cold_wakeref);
> > > > > +	aux_domain = intel_aux_ch_to_power_domain(dig_port-
> > > > > >aux_ch);
> > > > > +	intel_display_power_put_async(i915, aux_domain,
> > > > > tc_cold_wakeref);
> > > > > +}
> > > > > +
> > > > >  void intel_tc_port_unlock(struct intel_digital_port *dig_port)
> > > > >  {
> > > > >  	struct drm_i915_private *i915 = to_i915(dig_port-
> > > > > > base.base.dev);
> > > > >  	intel_wakeref_t wakeref = fetch_and_zero(&dig_port-
> > > > > > tc_lock_wakeref);
> > > > >  
> > > > > +	icl_tc_cold_unblock(dig_port);
> > > > > +
> > > > >  	mutex_unlock(&dig_port->tc_lock);
> > > > >  
> > > > > -	intel_display_power_put_async(i915,
> > > > > POWER_DOMAIN_DISPLAY_CORE,
> > > > > -				      wakeref);
> > > > > +	intel_display_power_put_async(i915,
> > > > > POWER_DOMAIN_DISPLAY_CORE,
> > > > > wakeref);
> > > > >  }
> > > > >  
> > > > >  bool intel_tc_port_ref_held(struct intel_digital_port
> > > > > *dig_port)
> > > > > @@ -548,6 +571,7 @@ void intel_tc_port_put_link(struct
> > > > > intel_digital_port *dig_port)
> > > > >  {
> > > > >  	mutex_lock(&dig_port->tc_lock);
> > > > >  	dig_port->tc_link_refcount--;
> > > > > +	icl_tc_cold_unblock(dig_port);
> > > > >  	mutex_unlock(&dig_port->tc_lock);
> > > > >  }
> > > > >  
> > > > > @@ -568,3 +592,22 @@ void intel_tc_port_init(struct
> > > > > intel_digital_port *dig_port, bool is_legacy)
> > > > >  	dig_port->tc_link_refcount = 0;
> > > > >  	tc_port_load_fia_params(i915, dig_port);
> > > > >  }
> > > > > +
> > > > > +void intel_tc_icl_tc_cold_exit(struct drm_i915_private *i915)
> > > > 
> > > > This could be in intel_display_power.c now, so we don't need to
> > > > export
> > > > it.
> > > 
> > > Okay.
> > > 
> > > > > +{
> > > > > +	int ret;
> > > > > +
> > > > > +	do {
> > > > > +		ret = sandybridge_pcode_write_timeout(i915,
> > > > > +						      ICL_PCODE
> > > > > _EXIT_TC
> > > > > COLD,
> > > > > +						      0, 250,
> > > > > 1);
> > > > > +
> > > > > +	} while (ret == -EAGAIN);
> > > > > +
> > > > > +	if (!ret)
> > > > > +		msleep(1);
> > > > 
> > > > Could you add a comment explaining that we need the sleep, since
> > > > according to BSpec the above request may not have completed even
> > > > though
> > > > it returned success?
> > > 
> > > Sure
> > > 
> > > > > +
> > > > > +	if (ret)
> > > > > +		drm_dbg_kms(&i915->drm, "TC cold block %s\n",
> > > > > +			    (ret == 0 ? "succeeded" :
> > > > > "failed"));
> > > > > +}
> > > > > diff --git a/drivers/gpu/drm/i915/display/intel_tc.h
> > > > > b/drivers/gpu/drm/i915/display/intel_tc.h
> > > > > index a1afcee48818..168d8896fcfd 100644
> > > > > --- a/drivers/gpu/drm/i915/display/intel_tc.h
> > > > > +++ b/drivers/gpu/drm/i915/display/intel_tc.h
> > > > > @@ -9,6 +9,7 @@
> > > > >  #include <linux/mutex.h>
> > > > >  #include <linux/types.h>
> > > > >  
> > > > > +struct drm_i915_private;
> > > > >  struct intel_digital_port;
> > > > >  
> > > > >  bool intel_tc_port_connected(struct intel_digital_port
> > > > > *dig_port);
> > > > > @@ -29,5 +30,6 @@ bool intel_tc_port_ref_held(struct
> > > > > intel_digital_port *dig_port);
> > > > >  void intel_tc_port_init(struct intel_digital_port *dig_port,
> > > > > bool
> > > > > is_legacy);
> > > > >  
> > > > >  u32 intel_tc_port_live_status_mask(struct intel_digital_port
> > > > > *dig_port);
> > > > > +void intel_tc_icl_tc_cold_exit(struct drm_i915_private *i915);
> > > > >  
> > > > >  #endif /* __INTEL_TC_H__ */
> > > > > diff --git a/drivers/gpu/drm/i915/i915_reg.h
> > > > > b/drivers/gpu/drm/i915/i915_reg.h
> > > > > index 17484345cb80..b111815d6596 100644
> > > > > --- a/drivers/gpu/drm/i915/i915_reg.h
> > > > > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > > > > @@ -9107,6 +9107,7 @@ enum {
> > > > >  #define     ICL_PCODE_MEM_SS_READ_QGV_POINT_INFO(point)	
> > > > > (((poin
> > > > > t) << 16) | (0x1 << 8))
> > > > >  #define   GEN6_PCODE_READ_D_COMP		0x10
> > > > >  #define   GEN6_PCODE_WRITE_D_COMP		0x11
> > > > > +#define   ICL_PCODE_EXIT_TCCOLD			0x12
> > > > >  #define   HSW_PCODE_DE_WRITE_FREQ_REQ		0x17
> > > > >  #define   DISPLAY_IPS_CONTROL			0x19
> > > > >              /* See also IPS_CTL */
> > > > > -- 
> > > > > 2.26.0
> > > > >

Patch
diff mbox series

diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c
index dbd61517ba63..1ccd57d645c7 100644
--- a/drivers/gpu/drm/i915/display/intel_display_power.c
+++ b/drivers/gpu/drm/i915/display/intel_display_power.c
@@ -592,9 +592,17 @@  icl_tc_phy_aux_power_well_enable(struct drm_i915_private *dev_priv,
 
 	_hsw_power_well_enable(dev_priv, power_well);
 
-	/* TODO ICL TC cold handling */
+	if (INTEL_GEN(dev_priv) == 11)
+		intel_tc_icl_tc_cold_exit(dev_priv);
 
-	_hsw_power_well_continue_enable(dev_priv, power_well);
+	/*
+	 * To avoid power well enable timeouts when disconnected or in TBT mode
+	 * when doing the TC cold exit sequence for GEN11
+	 */
+	if (INTEL_GEN(dev_priv) != 11 ||
+	    (intel_tc_port_live_status_mask(dig_port) &
+	     (TC_PORT_LEGACY | TC_PORT_DP_ALT)))
+		_hsw_power_well_continue_enable(dev_priv, power_well);
 
 	if (INTEL_GEN(dev_priv) >= 12 && !power_well->desc->hsw.is_tc_tbt) {
 		enum tc_port tc_port;
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 176ab5f1e867..a9a4a3c1b4d7 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1391,6 +1391,7 @@  struct intel_digital_port {
 	enum intel_display_power_domain ddi_io_power_domain;
 	struct mutex tc_lock;	/* protects the TypeC port mode */
 	intel_wakeref_t tc_lock_wakeref;
+	intel_wakeref_t tc_cold_wakeref;
 	int tc_link_refcount;
 	bool tc_legacy_port:1;
 	char tc_port_name[8];
diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
index d944be935423..b6d67f069ef7 100644
--- a/drivers/gpu/drm/i915/display/intel_tc.c
+++ b/drivers/gpu/drm/i915/display/intel_tc.c
@@ -7,6 +7,7 @@ 
 #include "intel_display.h"
 #include "intel_display_types.h"
 #include "intel_dp_mst.h"
+#include "intel_sideband.h"
 #include "intel_tc.h"
 
 static const char *tc_port_mode_name(enum tc_port_mode mode)
@@ -506,6 +507,13 @@  static void __intel_tc_port_lock(struct intel_digital_port *dig_port,
 
 	mutex_lock(&dig_port->tc_lock);
 
+	if (INTEL_GEN(i915) == 11 && dig_port->tc_link_refcount == 0) {
+		enum intel_display_power_domain aux_domain;
+
+		aux_domain = intel_aux_ch_to_power_domain(dig_port->aux_ch);
+		dig_port->tc_cold_wakeref = intel_display_power_get(i915, aux_domain);
+	}
+
 	if (!dig_port->tc_link_refcount &&
 	    intel_tc_port_needs_reset(dig_port))
 		intel_tc_port_reset_mode(dig_port, required_lanes);
@@ -519,15 +527,30 @@  void intel_tc_port_lock(struct intel_digital_port *dig_port)
 	__intel_tc_port_lock(dig_port, 1);
 }
 
+static void icl_tc_cold_unblock(struct intel_digital_port *dig_port)
+{
+	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
+	enum intel_display_power_domain aux_domain;
+	intel_wakeref_t tc_cold_wakeref;
+
+	if (INTEL_GEN(i915) != 11 || dig_port->tc_link_refcount > 0)
+		return;
+
+	tc_cold_wakeref = fetch_and_zero(&dig_port->tc_cold_wakeref);
+	aux_domain = intel_aux_ch_to_power_domain(dig_port->aux_ch);
+	intel_display_power_put_async(i915, aux_domain, tc_cold_wakeref);
+}
+
 void intel_tc_port_unlock(struct intel_digital_port *dig_port)
 {
 	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
 	intel_wakeref_t wakeref = fetch_and_zero(&dig_port->tc_lock_wakeref);
 
+	icl_tc_cold_unblock(dig_port);
+
 	mutex_unlock(&dig_port->tc_lock);
 
-	intel_display_power_put_async(i915, POWER_DOMAIN_DISPLAY_CORE,
-				      wakeref);
+	intel_display_power_put_async(i915, POWER_DOMAIN_DISPLAY_CORE, wakeref);
 }
 
 bool intel_tc_port_ref_held(struct intel_digital_port *dig_port)
@@ -548,6 +571,7 @@  void intel_tc_port_put_link(struct intel_digital_port *dig_port)
 {
 	mutex_lock(&dig_port->tc_lock);
 	dig_port->tc_link_refcount--;
+	icl_tc_cold_unblock(dig_port);
 	mutex_unlock(&dig_port->tc_lock);
 }
 
@@ -568,3 +592,22 @@  void intel_tc_port_init(struct intel_digital_port *dig_port, bool is_legacy)
 	dig_port->tc_link_refcount = 0;
 	tc_port_load_fia_params(i915, dig_port);
 }
+
+void intel_tc_icl_tc_cold_exit(struct drm_i915_private *i915)
+{
+	int ret;
+
+	do {
+		ret = sandybridge_pcode_write_timeout(i915,
+						      ICL_PCODE_EXIT_TCCOLD,
+						      0, 250, 1);
+
+	} while (ret == -EAGAIN);
+
+	if (!ret)
+		msleep(1);
+
+	if (ret)
+		drm_dbg_kms(&i915->drm, "TC cold block %s\n",
+			    (ret == 0 ? "succeeded" : "failed"));
+}
diff --git a/drivers/gpu/drm/i915/display/intel_tc.h b/drivers/gpu/drm/i915/display/intel_tc.h
index a1afcee48818..168d8896fcfd 100644
--- a/drivers/gpu/drm/i915/display/intel_tc.h
+++ b/drivers/gpu/drm/i915/display/intel_tc.h
@@ -9,6 +9,7 @@ 
 #include <linux/mutex.h>
 #include <linux/types.h>
 
+struct drm_i915_private;
 struct intel_digital_port;
 
 bool intel_tc_port_connected(struct intel_digital_port *dig_port);
@@ -29,5 +30,6 @@  bool intel_tc_port_ref_held(struct intel_digital_port *dig_port);
 void intel_tc_port_init(struct intel_digital_port *dig_port, bool is_legacy);
 
 u32 intel_tc_port_live_status_mask(struct intel_digital_port *dig_port);
+void intel_tc_icl_tc_cold_exit(struct drm_i915_private *i915);
 
 #endif /* __INTEL_TC_H__ */
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 17484345cb80..b111815d6596 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -9107,6 +9107,7 @@  enum {
 #define     ICL_PCODE_MEM_SS_READ_QGV_POINT_INFO(point)	(((point) << 16) | (0x1 << 8))
 #define   GEN6_PCODE_READ_D_COMP		0x10
 #define   GEN6_PCODE_WRITE_D_COMP		0x11
+#define   ICL_PCODE_EXIT_TCCOLD			0x12
 #define   HSW_PCODE_DE_WRITE_FREQ_REQ		0x17
 #define   DISPLAY_IPS_CONTROL			0x19
             /* See also IPS_CTL */