[PATCH 2/2] drm/i915/psr: Set frames before SU entry for psr2

[Vivi, Rodrigo]

> On Sep 20, 2017, at 7:33 AM, Nagaraju, Vathsala <vathsala.nagaraju at intel.com> wrote:
> 
> Set frames before SU entry value for max resync frame count of
> dpcd register 2009, bit field 0:3.
> 
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> CC: Puthikorn Voravootivat <puthik at chromium.org>
> Signed-off-by: Vathsala Nagaraju <vathsala.nagaraju at intel.com>
> ---
> drivers/gpu/drm/i915/intel_psr.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
> index acb5094..04b253f 100644
> --- a/drivers/gpu/drm/i915/intel_psr.c
> +++ b/drivers/gpu/drm/i915/intel_psr.c
> @@ -327,6 +327,7 @@ static void hsw_activate_psr2(struct intel_dp *intel_dp)
>     */
>    uint32_t idle_frames = max(6, dev_priv->vbt.psr.idle_frames);
>    uint32_t val;
> +    uint8_t sink_latency;
> 
>    val = idle_frames << EDP_PSR_IDLE_FRAME_SHIFT;
> 
> @@ -334,8 +335,15 @@ static void hsw_activate_psr2(struct intel_dp *intel_dp)
>     * mesh at all with our frontbuffer tracking. And the hw alone isn't
>     * good enough. */
>    val |= EDP_PSR2_ENABLE |
> -        EDP_SU_TRACK_ENABLE |
> -        EDP_FRAMES_BEFORE_SU_ENTRY;

Please also remove the definition of this su_entry since it was not following the new standards anyway...
Probably good to replace with function macro style for better use below...

> +        EDP_SU_TRACK_ENABLE;
> +
> +    if (drm_dp_dpcd_readb(&intel_dp->aux, DP_SINK_SYNCHRONIZATION_LATENCY,
> +                &sink_latency)) {
> +        sink_latency = sink_latency & DP_MAX_RESYNC_FRAME_CNT_MASK;
> +        val |= (sink_latency + 1) << EDP_PSR2_FRAME_BEFORE_SU_SHIFT;

... so you could use
val |= EDP_PSR2_FRAME_BEFORE_SU(sink_latency +1);


> +    } else {
> +        val |= EDP_FRAMES_BEFORE_SU_ENTRY;
> +    }
> 
>    if (dev_priv->vbt.psr.tp2_tp3_wakeup_time > 5)
>        val |= EDP_PSR2_TP2_TIME_2500;
> -- 
> 1.9.1
>