Re: [PATCH] drm/i915/psr: vbt change for psr

[Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>]

On Mon, 2018-05-14 at 09:02 +0530, vathsala nagaraju wrote:
> From: Vathsala Nagaraju <vathsala.nagaraju@intel.com>
> 
> For psr block #9, the vbt description has moved to options [0-3] for
> TP1,TP2,TP3 Wakeup time from decimal value without any change to vbt
> structure. Since spec does not  mention from which VBT version this
> change was added to vbt.bsf file, we cannot depend on bdb->version
> check
> to change for all the platforms.
> 
> There is RCR inplace for GOP team to  provide the version number
> to make generic change. Since Kabylake with bdb version 209 is having
> this
> change, limiting this change to gen9_bc and version 209+ to unblock
> google.
> 
> Tested on skl(bdb version 203,without options) and
> kabylake(bdb version 209,212) having new options.
> 
> bspec 20131
> 
> v2: (Jani and Rodrigo)
>     move the 165 version check to intel_bios.c
> v3: Jani
>     Move the abstraction to intel_bios.
> v4: Jani
>     Rename tp*_wakeup_time to have "us" suffix.
>     For values outside range[0-3],default to max 2500us.
>     Old decimal value was wake up time in multiples of 100us.
> v5: Jani and Rodrigo
>     Handle option 2 in default condition.
>     Print oustide range value.
>     For negetive values default to 2500us.
> v6: Jani
>     Handle default first and then fall through for case 2.
> v7: Rodrigo
>     Apply this change for IS_GEN9_BC and vbt version > 209
> 
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> CC: Puthikorn Voravootivat <puthik@chromium.org>
> 
> Signed-off-by: Maulik V Vaghela <maulik.v.vaghela@intel.com>
> Signed-off-by: Vathsala Nagaraju <vathsala.nagaraju@intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h   |  4 ++--
>  drivers/gpu/drm/i915/i915_reg.h   |  8 +++----
>  drivers/gpu/drm/i915/intel_bios.c | 46
> +++++++++++++++++++++++++++++++++++++--
>  drivers/gpu/drm/i915/intel_psr.c  | 39 +++++++++++++++++----------
> ------
>  4 files changed, 70 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h
> b/drivers/gpu/drm/i915/i915_drv.h
> index 57fb3aa..268b059 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1078,8 +1078,8 @@ struct intel_vbt_data {
>  		bool require_aux_wakeup;
>  		int idle_frames;
>  		enum psr_lines_to_wait lines_to_wait;
> -		int tp1_wakeup_time;
> -		int tp2_tp3_wakeup_time;
> +		int tp1_wakeup_time_us;
> +		int tp2_tp3_wakeup_time_us;
>  	} psr;
>  
>  	struct {
> diff --git a/drivers/gpu/drm/i915/i915_reg.h
> b/drivers/gpu/drm/i915/i915_reg.h
> index f11bb21..6820658 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -4088,10 +4088,10 @@ enum {
>  #define   EDP_Y_COORDINATE_ENABLE	(1<<25) /* GLK and CNL+ */
>  #define   EDP_MAX_SU_DISABLE_TIME(t)	((t)<<20)
>  #define   EDP_MAX_SU_DISABLE_TIME_MASK	(0x1f<<20)
> -#define   EDP_PSR2_TP2_TIME_500		(0<<8)
> -#define   EDP_PSR2_TP2_TIME_100		(1<<8)
> -#define   EDP_PSR2_TP2_TIME_2500	(2<<8)
> -#define   EDP_PSR2_TP2_TIME_50		(3<<8)
> +#define   EDP_PSR2_TP2_TIME_500us	(0<<8)
> +#define   EDP_PSR2_TP2_TIME_100us	(1<<8)
> +#define   EDP_PSR2_TP2_TIME_2500us	(2<<8)
> +#define   EDP_PSR2_TP2_TIME_50us	(3<<8)
>  #define   EDP_PSR2_TP2_TIME_MASK	(3<<8)
>  #define   EDP_PSR2_FRAME_BEFORE_SU_SHIFT 4
>  #define   EDP_PSR2_FRAME_BEFORE_SU_MASK	(0xf<<4)
> diff --git a/drivers/gpu/drm/i915/intel_bios.c
> b/drivers/gpu/drm/i915/intel_bios.c
> index 54270bd..695ca73 100644
> --- a/drivers/gpu/drm/i915/intel_bios.c
> +++ b/drivers/gpu/drm/i915/intel_bios.c
> @@ -688,8 +688,50 @@ static int intel_bios_ssc_frequency(struct
> drm_i915_private *dev_priv,
>  		break;
>  	}
>  
> -	dev_priv->vbt.psr.tp1_wakeup_time = psr_table-
> >tp1_wakeup_time;
> -	dev_priv->vbt.psr.tp2_tp3_wakeup_time = psr_table-
> >tp2_tp3_wakeup_time;
> +	/*
> +	 * New psr options 0=500us, 1=100us, 2=2500us, 3=0us
> +	 * Old decimal value is wake up time in multiples of 100 us.
> +	 */
> +	if (bdb->version >= 209 && IS_GEN9_BC(dev_priv)) {

Since this is the 'new' mapping, shouldn't this check be

if (version >= 209) {

}
i.e., what versions do BXT, GLK, CFL and CNL have?

Since gen-9 tables can have ambiguous interpretations, I think we can
do this.

if (version >= 209 || (IS_GEN9() && wakeup_time <=3)) {
	// Read this as {0:500, 1:100, 2:2500, 3:0}
} else {
	// Read this as wakeup_time * 100
}

This is assuming all versions => 209 use the new mapping consistently. 

2 and 3 are invalid values in the x*100 us scheme, so we can assume it
really means 2.5 ms and 0.
1 means the same.
0 is a problem, but we can check dpcd 0071h to confirm whether the sink
needs training or not. And it is safer to assume the sink needs
training at interpret is as 500 us.



> +		switch (psr_table->tp1_wakeup_time) {
> +		case 0:
> +			dev_priv->vbt.psr.tp1_wakeup_time_us = 500;
> +			break;
> +		case 1:
> +			dev_priv->vbt.psr.tp1_wakeup_time_us = 100;
> +			break;
> +		case 3:
> +			dev_priv->vbt.psr.tp1_wakeup_time_us = 0;
> +			break;
> +		default:
> +			DRM_DEBUG_KMS("VBT tp1 wakeup time value %d
> is outside range[0-3], defaulting to max value 2500us\n",
> +					psr_table->tp1_wakeup_time);
> +		case 2:
> +			dev_priv->vbt.psr.tp1_wakeup_time_us = 2500;
> +			break;
> +		}
> +

nit: That's an interesting order, it is neither sorted by the switch
variable nor by wake up time. It is easier to read if you chose one way
or the other IMO.

 
> +		switch (psr_table->tp2_tp3_wakeup_time) {
> +		case 0:
> +			dev_priv->vbt.psr.tp2_tp3_wakeup_time_us =
> 500;
> +			break;
> +		case 1:
> +			dev_priv->vbt.psr.tp2_tp3_wakeup_time_us =
> 100;
> +			break;
> +		case 3:
> +			dev_priv->vbt.psr.tp1_wakeup_time_us = 0;
> +			break;
> +		default:
> +			DRM_DEBUG_KMS("VBT tp2_tp3 wakeup time value
> %d is outside range[0-3], defaulting to max value 2500us\n",
> +					psr_table-
> >tp2_tp3_wakeup_time);
> +		case 2:
> +			dev_priv->vbt.psr.tp2_tp3_wakeup_time_us =
> 2500;
> +		break;
> +		}
> +	} else {
> +		dev_priv->vbt.psr.tp1_wakeup_time_us = psr_table-
> >tp1_wakeup_time * 100;
> +		dev_priv->vbt.psr.tp2_tp3_wakeup_time_us =
> psr_table->tp2_tp3_wakeup_time * 100;

> +	}
>  }
>  
>  static void parse_dsi_backlight_ports(struct drm_i915_private
> *dev_priv,
> diff --git a/drivers/gpu/drm/i915/intel_psr.c
> b/drivers/gpu/drm/i915/intel_psr.c
> index db27f2f..d64f039 100644
> --- a/drivers/gpu/drm/i915/intel_psr.c
> +++ b/drivers/gpu/drm/i915/intel_psr.c
> @@ -461,23 +461,23 @@ static void hsw_activate_psr1(struct intel_dp
> *intel_dp)
>  	if (dev_priv->psr.link_standby)
>  		val |= EDP_PSR_LINK_STANDBY;
>  
> -	if (dev_priv->vbt.psr.tp1_wakeup_time > 5)
> -		val |= EDP_PSR_TP1_TIME_2500us;
> -	else if (dev_priv->vbt.psr.tp1_wakeup_time > 1)
> -		val |= EDP_PSR_TP1_TIME_500us;
> -	else if (dev_priv->vbt.psr.tp1_wakeup_time > 0)
> +	if (dev_priv->vbt.psr.tp1_wakeup_time_us == 0)
> +		val |=  EDP_PSR_TP1_TIME_0us;
> +	else if (dev_priv->vbt.psr.tp1_wakeup_time_us <= 100)
>  		val |= EDP_PSR_TP1_TIME_100us;
> +	else if (dev_priv->vbt.psr.tp1_wakeup_time_us <= 500)
> +		val |= EDP_PSR_TP1_TIME_500us;
>  	else
> -		val |= EDP_PSR_TP1_TIME_0us;
> +		val |= EDP_PSR_TP1_TIME_2500us;
>  
> -	if (dev_priv->vbt.psr.tp2_tp3_wakeup_time > 5)
> -		val |= EDP_PSR_TP2_TP3_TIME_2500us;
> -	else if (dev_priv->vbt.psr.tp2_tp3_wakeup_time > 1)
> -		val |= EDP_PSR_TP2_TP3_TIME_500us;
> -	else if (dev_priv->vbt.psr.tp2_tp3_wakeup_time > 0)
> +	if (dev_priv->vbt.psr.tp2_tp3_wakeup_time_us == 0)
> +		val |=  EDP_PSR_TP2_TP3_TIME_0us;
> +	else if (dev_priv->vbt.psr.tp2_tp3_wakeup_time_us <= 100)
>  		val |= EDP_PSR_TP2_TP3_TIME_100us;
> +	else if (dev_priv->vbt.psr.tp2_tp3_wakeup_time_us <= 500)
> +		val |= EDP_PSR_TP2_TP3_TIME_500us;
>  	else
> -		val |= EDP_PSR_TP2_TP3_TIME_0us;
> +		val |= EDP_PSR_TP2_TP3_TIME_2500us;
>  
>  	if (intel_dp_source_supports_hbr2(intel_dp) &&
>  	    drm_dp_tps3_supported(intel_dp->dpcd))
> @@ -513,14 +513,15 @@ static void hsw_activate_psr2(struct intel_dp
> *intel_dp)
>  
>  	val |= EDP_PSR2_FRAME_BEFORE_SU(dev_priv-
> >psr.sink_sync_latency + 1);
>  
> -	if (dev_priv->vbt.psr.tp2_tp3_wakeup_time > 5)
> -		val |= EDP_PSR2_TP2_TIME_2500;
> -	else if (dev_priv->vbt.psr.tp2_tp3_wakeup_time > 1)
> -		val |= EDP_PSR2_TP2_TIME_500;
> -	else if (dev_priv->vbt.psr.tp2_tp3_wakeup_time > 0)
> -		val |= EDP_PSR2_TP2_TIME_100;
> +	if (dev_priv->vbt.psr.tp2_tp3_wakeup_time_us >= 0 &&
> +	    dev_priv->vbt.psr.tp2_tp3_wakeup_time_us <= 50)
> +		val |= EDP_PSR2_TP2_TIME_50us;
> +	else if (dev_priv->vbt.psr.tp2_tp3_wakeup_time_us <= 100)
> +		val |= EDP_PSR2_TP2_TIME_100us;
> +	else if (dev_priv->vbt.psr.tp2_tp3_wakeup_time_us <= 500)
> +		val |= EDP_PSR2_TP2_TIME_500us;
>  	else
> -		val |= EDP_PSR2_TP2_TIME_50;
> +		val |= EDP_PSR2_TP2_TIME_2500us;
>  
>  	I915_WRITE(EDP_PSR2_CTL, val);
>  }
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