On Tue, Sep 28, 2021 at 03:14:45AM +0300, Souza, Jose wrote:
> On Tue, 2021-09-28 at 02:51 +0300, Imre Deak wrote:
> > On Tue, Sep 28, 2021 at 02:33:27AM +0300, Souza, Jose wrote:
> > > On Tue, 2021-09-28 at 01:28 +0300, Imre Deak wrote:
> > > > On Tue, Sep 28, 2021 at 01:21:21AM +0300, Souza, Jose wrote:
> > > > > On Tue, 2021-09-28 at 01:13 +0300, Imre Deak wrote:
> > > > > > On Tue, Sep 28, 2021 at 12:56:24AM +0300, Souza, Jose wrote:
> > > > > > > On Tue, 2021-09-21 at 03:23 +0300, Imre Deak wrote:
> > > > > > > > A follow-up change will select the TC-cold blocking power 
> > > > > > > > domain based
> > > > > > > > on the TypeC mode, prepare for that here.
> > > > > > > > 
> > > > > > > > Also bring intel_tc_cold_requires_aux_pw() earlier to its 
> > > > > > > > logical place
> > > > > > > > for readability.
> > > > > > > > 
> > > > > > > > No functional change.
> > > > > > > > 
> > > > > > > > Cc: José Roberto de Souza <jose.so...@intel.com>
> > > > > > > > Signed-off-by: Imre Deak <imre.d...@intel.com>
> > > > > > > > ---
> > > > > > > >  .../drm/i915/display/intel_display_types.h    |  2 +
> > > > > > > >  drivers/gpu/drm/i915/display/intel_tc.c       | 63 
> > > > > > > > +++++++++++--------
> > > > > > > >  2 files changed, 39 insertions(+), 26 deletions(-)
> > > > > > > > 
> > > > > > > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h 
> > > > > > > > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > > > > > index e9e806d90eec4..08a73ffded957 100644
> > > > > > > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > > > > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > > > > > @@ -1663,8 +1663,10 @@ struct intel_digital_port {
> > > > > > > >         enum intel_display_power_domain ddi_io_power_domain;
> > > > > > > >         intel_wakeref_t ddi_io_wakeref;
> > > > > > > >         intel_wakeref_t aux_wakeref;
> > > > > > > > +
> > > > > > > >         struct mutex tc_lock;   /* protects the TypeC port mode 
> > > > > > > > */
> > > > > > > >         intel_wakeref_t tc_lock_wakeref;
> > > > > > > > +       enum intel_display_power_domain tc_lock_power_domain;
> > > > > > > >         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 77b16a7c43466..24d2dc2e19a7d 100644
> > > > > > > > --- a/drivers/gpu/drm/i915/display/intel_tc.c
> > > > > > > > +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> > > > > > > > @@ -48,8 +48,16 @@ bool intel_tc_port_in_legacy_mode(struct 
> > > > > > > > intel_digital_port *dig_port)
> > > > > > > >         return intel_tc_port_in_mode(dig_port, TC_PORT_LEGACY);
> > > > > > > >  }
> > > > > > > >  
> > > > > > > > +bool intel_tc_cold_requires_aux_pw(struct intel_digital_port 
> > > > > > > > *dig_port)
> > > > > > > > +{
> > > > > > > > +       struct drm_i915_private *i915 = 
> > > > > > > > to_i915(dig_port->base.base.dev);
> > > > > > > > +
> > > > > > > > +       return (DISPLAY_VER(i915) == 11 && 
> > > > > > > > dig_port->tc_legacy_port) ||
> > > > > > > > +               IS_ALDERLAKE_P(i915);
> > > > > > > > +}
> > > > > > > > +
> > > > > > > >  static enum intel_display_power_domain
> > > > > > > > -tc_cold_get_power_domain(struct intel_digital_port *dig_port)
> > > > > > > > +tc_cold_get_power_domain(struct intel_digital_port *dig_port, 
> > > > > > > > enum tc_port_mode mode)
> > > > > > > >  {
> > > > > > > >         if (intel_tc_cold_requires_aux_pw(dig_port))
> > > > > > > >                 return 
> > > > > > > > intel_legacy_aux_to_power_domain(dig_port->aux_ch);
> > > > > > > > @@ -58,23 +66,30 @@ tc_cold_get_power_domain(struct 
> > > > > > > > intel_digital_port *dig_port)
> > > > > > > >  }
> > > > > > > >  
> > > > > > > >  static intel_wakeref_t
> > > > > > > > -tc_cold_block(struct intel_digital_port *dig_port)
> > > > > > > > +tc_cold_block_in_mode(struct intel_digital_port *dig_port, 
> > > > > > > > enum tc_port_mode mode,
> > > > > > > > +                     enum intel_display_power_domain *domain)
> > > > > > > >  {
> > > > > > > >         struct drm_i915_private *i915 = 
> > > > > > > > to_i915(dig_port->base.base.dev);
> > > > > > > > -       enum intel_display_power_domain domain;
> > > > > > > >  
> > > > > > > >         if (DISPLAY_VER(i915) == 11 && 
> > > > > > > > !dig_port->tc_legacy_port)
> > > > > > > >                 return 0;
> > > > > > > >  
> > > > > > > > -       domain = tc_cold_get_power_domain(dig_port);
> > > > > > > > -       return intel_display_power_get(i915, domain);
> > > > > > > > +       *domain = tc_cold_get_power_domain(dig_port, mode);
> > > > > > > 
> > > > > > > I see problems with this approach.
> > > > > > > 
> > > > > > > If there is a TC alt-mode is connected and current software state 
> > > > > > > is
> > > > > > > TBT or disconnected it will not get the power domain to exit TC 
> > > > > > > cold,
> > > > > > > what could case invalid reads of registers.
> > > > > > 
> > > > > > If the mode needs to be changed, like in the above cases, the power
> > > > > > domain required to exit TC cold will be taken.
> > > > > 
> > > > > How?
> > > > > I see at least this 2 problematic cases.
> > > > > 
> > > > > intel_tc_port_sanitize()
> > > > >       tc_cold_block(mode=TBT)
> > > > 
> > > > It's in disconnected mode at this point.
> > > 
> > > Okay.
> > > 
> > > > 
> > > > > 
> > > > >       dig_port->tc_mode = intel_tc_port_get_current_mode(dig_port);
> > > > >       ...
> > > > > 
> > > > >       tc_cold_unblock(dig_port, domain, tc_cold_wref);
> > > > > 
> > > > > Other case
> > > > > 
> > > > > intel_tc_port_connected()
> > > > > 
> > > > >       tc_cold_block(mode=TBT)
> > > > 
> > > > Reading PORT_TX_DFLEXDPSP while in TC-cold returns 0xffffffff, and it's
> > > > handled when reading it (which is also required by the spec).
> > > 
> > > Will only follow adl-p flow for this
> > > example, https://pastebin.com/raw/TVXdK1Et (pastebin just to make sure
> > > indentation is not lost between email clients)
> > 
> > TCSS_DDI_STATUS is in IOM (so neither a FIA or a PHY register). From Bspec 
> > 55480:
> > """
> > Type-C Flow Registers Used by Display Software
> > ...
> > Location          Register
> > IOM               TCSS_DDI_STATUS
> > """
> > 
> > and IOM registers are accessible in TC-cold:
> > 
> > """
> > TCCOLD
> > The type-C subsystem can enter the TCCOLD power saving state where FIA and 
> > type-C
> > PHY registers become inaccessible and respond to reads with all 1s data,
> > while IOM remains accessible. 
> 
> Ohh okay, maybe add some comments about the above.

Ok, can add something to adl_tc_port_live_status_mask().

> For TGL taking POWER_DOMAIN_TC_COLD_OFF will solve everything.
> 
> What about ICL in legacy mode, when going from TC_PORT_TBT_ALT to
> TC_PORT_LEGACY.  Reading PORT_TX_DFLEXDPSP in icl_tc_port_live_status_mask()
> will set mask to BIT(TC_PORT_TBT_ALT) | BIT(TC_PORT_DP_ALT) | 
> BIT(TC_PORT_LEGACY).

Yes on ICL, we don't have any way to block TC-cold in TBT mode (on
systems with TBT/DP-alt ports, there is no TC-cold blocking PUNIT
command in the firmwares). Hence we compare the reads against all 1s. 

In any case normally it's not possible to switch from TBT/DP-alt to
legacy, since legacy is fixed/hardwired.

> That would not be a problem if SDEISR bit for TC port is always set
> when in legacy mode.  Do you know what is the behavior here?

SDEISR is in the south display, so shouldn't be affected by TC-cold.

We could check this bit even if DFLEXDPSP returns all 1s, to account for
incorrect VBTs (and let tc_port_fixup_legacy_flag() fix things up). But
that would be for a follow-up since it's not handled in the current code
either.

> The handling for going from TC_PORT_DISCONNECTED to TC_PORT_LEGACY is 
> properly handled.
> 
> 
> > """
> > 
> > > > >                      BIT(dig_port->tc_mode);
> > > > > 
> > > > >       tc_cold_unblock(dig_port, domain, tc_cold_wref);
> > > > > 
> > > > > 
> > > > > > 
> > > > > > > From the next patch commit message: 'For the ADL-P TBT mode the 
> > > > > > > spec
> > > > > > > doesn't require blocking TC-cold by using the legacy AUX power
> > > > > > > domain'.
> > > > > > > 
> > > > > > > It is not required for TBT but when there is nothing connected,
> > > > > > > hardware is not in TBT mode so it can still get into TC cold.
> > > > > > 
> > > > > > If there is nothing connected the required power domain will be 
> > > > > > taken to
> > > > > > exit TC cold.
> > > > > > 
> > > > > > > > +
> > > > > > > > +       return intel_display_power_get(i915, *domain);
> > > > > > > > +}
> > > > > > > > +
> > > > > > > > +static intel_wakeref_t
> > > > > > > > +tc_cold_block(struct intel_digital_port *dig_port, enum 
> > > > > > > > intel_display_power_domain *domain)
> > > > > > > > +{
> > > > > > > > +       return tc_cold_block_in_mode(dig_port, 
> > > > > > > > dig_port->tc_mode, domain);
> > > > > > > >  }
> > > > > > > >  
> > > > > > > >  static void
> > > > > > > > -tc_cold_unblock(struct intel_digital_port *dig_port, 
> > > > > > > > intel_wakeref_t wakeref)
> > > > > > > > +tc_cold_unblock(struct intel_digital_port *dig_port, enum 
> > > > > > > > intel_display_power_domain domain,
> > > > > > > > +               intel_wakeref_t wakeref)
> > > > > > > >  {
> > > > > > > >         struct drm_i915_private *i915 = 
> > > > > > > > to_i915(dig_port->base.base.dev);
> > > > > > > > -       enum intel_display_power_domain domain;
> > > > > > > >  
> > > > > > > >         /*
> > > > > > > >          * wakeref == -1, means some error happened saving 
> > > > > > > > save_depot_stack but
> > > > > > > > @@ -84,8 +99,7 @@ tc_cold_unblock(struct intel_digital_port 
> > > > > > > > *dig_port, intel_wakeref_t wakeref)
> > > > > > > >         if (wakeref == 0)
> > > > > > > >                 return;
> > > > > > > >  
> > > > > > > > -       domain = tc_cold_get_power_domain(dig_port);
> > > > > > > > -       intel_display_power_put_async(i915, domain, wakeref);
> > > > > > > > +       intel_display_power_put(i915, domain, wakeref);
> > > > > > > >  }
> > > > > > > >  
> > > > > > > >  static void
> > > > > > > > @@ -98,7 +112,8 @@ assert_tc_cold_blocked(struct 
> > > > > > > > intel_digital_port *dig_port)
> > > > > > > >                 return;
> > > > > > > >  
> > > > > > > >         enabled = intel_display_power_is_enabled(i915,
> > > > > > > > -                                                
> > > > > > > > tc_cold_get_power_domain(dig_port));
> > > > > > > > +                                                
> > > > > > > > tc_cold_get_power_domain(dig_port,
> > > > > > > > +                                                               
> > > > > > > >           dig_port->tc_mode));
> > > > > > > >         drm_WARN_ON(&i915->drm, !enabled);
> > > > > > > >  }
> > > > > > > >  
> > > > > > > > @@ -634,7 +649,8 @@ void intel_tc_port_sanitize(struct 
> > > > > > > > intel_digital_port *dig_port)
> > > > > > > >  
> > > > > > > >         drm_WARN_ON(&i915->drm, dig_port->tc_mode != 
> > > > > > > > TC_PORT_DISCONNECTED);
> > > > > > > >         if (active_links) {
> > > > > > > > -               intel_wakeref_t tc_cold_wref = 
> > > > > > > > tc_cold_block(dig_port);
> > > > > > > > +               enum intel_display_power_domain domain;
> > > > > > > > +               intel_wakeref_t tc_cold_wref = 
> > > > > > > > tc_cold_block(dig_port, &domain);
> > > > > > > >  
> > > > > > > >                 dig_port->tc_mode = 
> > > > > > > > intel_tc_port_get_current_mode(dig_port);
> > > > > > > >  
> > > > > > > > @@ -644,7 +660,7 @@ void intel_tc_port_sanitize(struct 
> > > > > > > > intel_digital_port *dig_port)
> > > > > > > >                                     dig_port->tc_port_name, 
> > > > > > > > active_links);
> > > > > > > >                 intel_tc_port_link_init_refcount(dig_port, 
> > > > > > > > active_links);
> > > > > > > >  
> > > > > > > > -               tc_cold_unblock(dig_port, tc_cold_wref);
> > > > > > > > +               tc_cold_unblock(dig_port, domain, tc_cold_wref);
> > > > > > > >         }
> > > > > > > >  
> > > > > > > >         drm_dbg_kms(&i915->drm, "Port %s: sanitize mode (%s)\n",
> > > > > > > > @@ -673,15 +689,16 @@ bool intel_tc_port_connected(struct 
> > > > > > > > intel_encoder *encoder)
> > > > > > > >  {
> > > > > > > >         struct intel_digital_port *dig_port = 
> > > > > > > > enc_to_dig_port(encoder);
> > > > > > > >         bool is_connected;
> > > > > > > > +       enum intel_display_power_domain domain;
> > > > > > > >         intel_wakeref_t tc_cold_wref;
> > > > > > > >  
> > > > > > > >         intel_tc_port_lock(dig_port);
> > > > > > > > -       tc_cold_wref = tc_cold_block(dig_port);
> > > > > > > > +       tc_cold_wref = tc_cold_block(dig_port, &domain);
> > > > > > > >  
> > > > > > > >         is_connected = tc_port_live_status_mask(dig_port) &
> > > > > > > >                        BIT(dig_port->tc_mode);
> > > > > > > >  
> > > > > > > > -       tc_cold_unblock(dig_port, tc_cold_wref);
> > > > > > > > +       tc_cold_unblock(dig_port, domain, tc_cold_wref);
> > > > > > > >         intel_tc_port_unlock(dig_port);
> > > > > > > >  
> > > > > > > >         return is_connected;
> > > > > > > > @@ -698,15 +715,16 @@ static void __intel_tc_port_lock(struct 
> > > > > > > > intel_digital_port *dig_port,
> > > > > > > >         mutex_lock(&dig_port->tc_lock);
> > > > > > > >  
> > > > > > > >         if (!dig_port->tc_link_refcount) {
> > > > > > > > +               enum intel_display_power_domain domain;
> > > > > > > >                 intel_wakeref_t tc_cold_wref;
> > > > > > > >  
> > > > > > > > -               tc_cold_wref = tc_cold_block(dig_port);
> > > > > > > > +               tc_cold_wref = tc_cold_block(dig_port, &domain);
> > > > > > > >  
> > > > > > > >                 if (force_disconnect || 
> > > > > > > > intel_tc_port_needs_reset(dig_port))
> > > > > > > >                         intel_tc_port_reset_mode(dig_port, 
> > > > > > > > required_lanes,
> > > > > > > >                                                  
> > > > > > > > force_disconnect);
> > > > > > > >  
> > > > > > > > -               tc_cold_unblock(dig_port, tc_cold_wref);
> > > > > > > > +               tc_cold_unblock(dig_port, domain, tc_cold_wref);
> > > > > > > >         }
> > > > > > > >  
> > > > > > > >         drm_WARN_ON(&i915->drm, dig_port->tc_mode == 
> > > > > > > > TC_PORT_DISCONNECTED);
> > > > > > > > @@ -775,6 +793,7 @@ void intel_tc_port_put_link(struct 
> > > > > > > > intel_digital_port *dig_port)
> > > > > > > >  static bool
> > > > > > > >  tc_has_modular_fia(struct drm_i915_private *i915, struct 
> > > > > > > > intel_digital_port *dig_port)
> > > > > > > >  {
> > > > > > > > +       enum intel_display_power_domain domain;
> > > > > > > >         intel_wakeref_t wakeref;
> > > > > > > >         u32 val;
> > > > > > > >  
> > > > > > > > @@ -782,9 +801,9 @@ tc_has_modular_fia(struct drm_i915_private 
> > > > > > > > *i915, struct intel_digital_port *dig
> > > > > > > >                 return false;
> > > > > > > >  
> > > > > > > >         mutex_lock(&dig_port->tc_lock);
> > > > > > > > -       wakeref = tc_cold_block(dig_port);
> > > > > > > > +       wakeref = tc_cold_block(dig_port, &domain);
> > > > > > > >         val = intel_uncore_read(&i915->uncore, 
> > > > > > > > PORT_TX_DFLEXDPSP(FIA1));
> > > > > > > > -       tc_cold_unblock(dig_port, wakeref);
> > > > > > > > +       tc_cold_unblock(dig_port, domain, wakeref);
> > > > > > > >         mutex_unlock(&dig_port->tc_lock);
> > > > > > > >  
> > > > > > > >         drm_WARN_ON(&i915->drm, val == 0xffffffff);
> > > > > > > > @@ -829,11 +848,3 @@ 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);
> > > > > > > >  }
> > > > > > > > -
> > > > > > > > -bool intel_tc_cold_requires_aux_pw(struct intel_digital_port 
> > > > > > > > *dig_port)
> > > > > > > > -{
> > > > > > > > -       struct drm_i915_private *i915 = 
> > > > > > > > to_i915(dig_port->base.base.dev);
> > > > > > > > -
> > > > > > > > -       return (DISPLAY_VER(i915) == 11 && 
> > > > > > > > dig_port->tc_legacy_port) ||
> > > > > > > > -               IS_ALDERLAKE_P(i915);
> > > > > > > > -}
> > > > > > > 
> > > > > 
> > > 
> 

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