[Intel-gfx] [PATCH 6/6] drm/i915/tc/tgl: Implement TC cold sequences

Imre Deak imre.deak at intel.com
Wed Apr 1 12:55:57 UTC 2020


On Tue, Mar 31, 2020 at 05:41:20PM -0700, José Roberto de Souza wrote:
> TC ports can enter in TCCOLD to save power and is required to request
> to PCODE to exit this state before use or read to TC registers.
> 
> For TGL there is a new MBOX command to do that with a parameter to ask
> PCODE to exit and block TCCOLD entry or unblock TCCOLD entry.
> 
> So adding a new power domain to reuse the refcount and only allow
> TC cold when all TC ports are not in use.
> 
> BSpec: 49294
> Cc: Imre Deak <imre.deak at intel.com>
> Cc: Cooper Chiou <cooper.chiou at intel.com>
> Cc: Kai-Heng Feng <kai.heng.feng at canonical.com>
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> ---
>  .../drm/i915/display/intel_display_power.c    | 46 ++++++++++++++
>  .../drm/i915/display/intel_display_power.h    |  1 +
>  drivers/gpu/drm/i915/display/intel_tc.c       | 63 +++++++++++++++----
>  drivers/gpu/drm/i915/display/intel_tc.h       |  1 +
>  drivers/gpu/drm/i915/i915_reg.h               |  3 +
>  5 files changed, 103 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c
> index 1ccd57d645c7..5de115583146 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_power.c
> @@ -2842,6 +2842,8 @@ void intel_display_power_put(struct drm_i915_private *dev_priv,
>  #define TGL_AUX_I_TBT6_IO_POWER_DOMAINS (	\
>  	BIT_ULL(POWER_DOMAIN_AUX_I_TBT))
>  
> +#define TGL_TC_COLD_OFF (BIT_ULL(POWER_DOMAIN_TC_COLD_OFF))

TGL_TC_COLD_OFF_POWER_DOMAINS
and should also include all the AUX power domains.

> +
>  static const struct i915_power_well_ops i9xx_always_on_power_well_ops = {
>  	.sync_hw = i9xx_power_well_sync_hw_noop,
>  	.enable = i9xx_always_on_power_well_noop,
> @@ -3944,6 +3946,44 @@ static const struct i915_power_well_desc ehl_power_wells[] = {
>  	},
>  };
>  
> +static void
> +tgl_tc_cold_off_power_well_enable(struct drm_i915_private *i915,
> +				  struct i915_power_well *power_well)
> +{
> +	intel_tc_tgl_tc_cold_request(i915, true);
> +}
> +
> +static void
> +tgl_tc_cold_off_power_well_disable(struct drm_i915_private *i915,
> +				   struct i915_power_well *power_well)
> +{
> +	intel_tc_tgl_tc_cold_request(i915, false);
> +}
> +
> +static void
> +tgl_tc_cold_off_power_well_sync_hw(struct drm_i915_private *i915,
> +				   struct i915_power_well *power_well)
> +{
> +	if (power_well->count > 0)
> +		tgl_tc_cold_off_power_well_enable(i915, power_well);
> +	else
> +		tgl_tc_cold_off_power_well_disable(i915, power_well);
> +}
> +
> +static bool tgl_tc_cold_off_power_well_is_enabled(struct drm_i915_private *dev_priv,
> +						  struct i915_power_well *power_well)
> +{
> +	/* There is no way to just read it from PCODE */
> +	return false;
> +}
> +
> +static const struct i915_power_well_ops tgl_tc_cold_off_ops = {
> +	.sync_hw = tgl_tc_cold_off_power_well_sync_hw,
> +	.enable = tgl_tc_cold_off_power_well_enable,
> +	.disable = tgl_tc_cold_off_power_well_disable,
> +	.is_enabled = tgl_tc_cold_off_power_well_is_enabled,
> +};
> +
>  static const struct i915_power_well_desc tgl_power_wells[] = {
>  	{
>  		.name = "always-on",
> @@ -4271,6 +4311,12 @@ static const struct i915_power_well_desc tgl_power_wells[] = {
>  			.hsw.irq_pipe_mask = BIT(PIPE_D),
>  		},
>  	},
> +	{
> +		.name = "TC cold off",
> +		.domains = POWER_DOMAIN_TC_COLD_OFF,

TGL_TC_COLD_OFF_POWER_DOMAINS

> +		.ops = &tgl_tc_cold_off_ops,
> +		.id = DISP_PW_ID_NONE,
> +	},
>  };
>  
>  static int
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.h b/drivers/gpu/drm/i915/display/intel_display_power.h
> index da64a5edae7a..070457e7b948 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_power.h
> @@ -76,6 +76,7 @@ enum intel_display_power_domain {
>  	POWER_DOMAIN_MODESET,
>  	POWER_DOMAIN_GT_IRQ,
>  	POWER_DOMAIN_DPLL_DC_OFF,
> +	POWER_DOMAIN_TC_COLD_OFF,
>  	POWER_DOMAIN_INIT,
>  
>  	POWER_DOMAIN_NUM,
> diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
> index b6d67f069ef7..58f19037411a 100644
> --- a/drivers/gpu/drm/i915/display/intel_tc.c
> +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> @@ -507,11 +507,16 @@ 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;
> +	if (dig_port->tc_link_refcount == 0) {
> +		enum intel_display_power_domain 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 (INTEL_GEN(i915) == 11)
> +			domain = intel_aux_ch_to_power_domain(dig_port->aux_ch);
> +		else
> +			domain = POWER_DOMAIN_TC_COLD_OFF;
> +
> +		dig_port->tc_cold_wakeref = intel_display_power_get(i915,
> +								    domain);
>  	}
>  
>  	if (!dig_port->tc_link_refcount &&
> @@ -527,18 +532,23 @@ 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)
> +static void 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;
> +	enum intel_display_power_domain domain;
>  	intel_wakeref_t tc_cold_wakeref;
>  
> -	if (INTEL_GEN(i915) != 11 || dig_port->tc_link_refcount > 0)
> +	if (dig_port->tc_link_refcount > 0)

You could drop the ref whenever wakeref passed to this function is not NULL. 

>  		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);
> +
> +	if (INTEL_GEN(i915) == 11)
> +		domain = intel_aux_ch_to_power_domain(dig_port->aux_ch);
> +	else
> +		domain = POWER_DOMAIN_TC_COLD_OFF;
> +
> +	intel_display_power_put_async(i915, domain, tc_cold_wakeref);
>  }
>  
>  void intel_tc_port_unlock(struct intel_digital_port *dig_port)
> @@ -546,7 +556,7 @@ 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);
> +	tc_cold_unblock(dig_port);
>  
>  	mutex_unlock(&dig_port->tc_lock);
>  
> @@ -571,7 +581,7 @@ 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);
> +	tc_cold_unblock(dig_port);
>  	mutex_unlock(&dig_port->tc_lock);
>  }
>  
> @@ -611,3 +621,34 @@ void intel_tc_icl_tc_cold_exit(struct drm_i915_private *i915)
>  		drm_dbg_kms(&i915->drm, "TC cold block %s\n",
>  			    (ret == 0 ? "succeeded" : "failed"));
>  }
> +
> +void
> +intel_tc_tgl_tc_cold_request(struct drm_i915_private *i915, bool block)
> +{
> +	u32 low_val, high_val;
> +	u8 tries = 0;
> +	int ret;
> +
> +	do {
> +		low_val = 0;
> +		high_val = block ? 0 : TGL_PCODE_EXIT_TCCOLD_DATA_H_UNBLOCK_REQ;
> +
> +		ret = sandybridge_pcode_read(i915, TGL_PCODE_TCCOLD, &low_val,
> +					     &high_val);
> +		if (ret == 0) {
> +			if (block &&
> +			    (low_val & TGL_PCODE_EXIT_TCCOLD_DATA_L_EXIT_FAILED))
> +				ret = -EIO;
> +			else
> +				break;
> +		}
> +
> +		if (ret != -EAGAIN)
> +			tries++;
> +	} while (tries < 3);
> +
> +	if (ret)
> +		drm_dbg_kms(&i915->drm, "TC cold %sblock %s\n",
> +			    (block ? "" : "un"),
> +			    (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 168d8896fcfd..8bb358cc8f15 100644
> --- a/drivers/gpu/drm/i915/display/intel_tc.h
> +++ b/drivers/gpu/drm/i915/display/intel_tc.h
> @@ -31,5 +31,6 @@ 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);
> +void intel_tc_tgl_tc_cold_request(struct drm_i915_private *i915, bool block);
>  
>  #endif /* __INTEL_TC_H__ */
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index b111815d6596..5548f3b56c0b 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -9110,6 +9110,9 @@ enum {
>  #define   ICL_PCODE_EXIT_TCCOLD			0x12
>  #define   HSW_PCODE_DE_WRITE_FREQ_REQ		0x17
>  #define   DISPLAY_IPS_CONTROL			0x19
> +#define   TGL_PCODE_TCCOLD			0x26
> +#define     TGL_PCODE_EXIT_TCCOLD_DATA_L_EXIT_FAILED   REG_BIT(0)
> +#define     TGL_PCODE_EXIT_TCCOLD_DATA_H_UNBLOCK_REQ   REG_BIT(0)
>              /* See also IPS_CTL */
>  #define     IPS_PCODE_CONTROL			(1 << 30)
>  #define   HSW_PCODE_DYNAMIC_DUTY_CYCLE_CONTROL	0x1A
> -- 
> 2.26.0
> 


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