On Wed, 2018-04-18 at 15:43 -0700, José Roberto de Souza wrote:
> Sink can be configured to calculate the CRC over the static frame and
> compare with the CRC calculated and transmited in the VSC SDP by
> source, if there is a mismatch sink will do a short pulse in HPD
> and set DP_PSR_LINK_CRC_ERROR on DP_PSR_ERROR_STATUS.
>
> Also spec recommends to disable MAX_SLEEP as a trigger to exit PSR
> when
> CRC check is enabled to improve power savings.
Let's mask this irrespective of CRC's, i.e., for HSW too. It'll make
PSR exit more deterministic.
Cc: Ville
I remember Ville was asking if there's a way to disable the timeouts a
while ago.
>
> Spec: 7723
>
> Signed-off-by: José Roberto de Souza <jose.souza@xxxxxxxxx>
> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@xxxxxxxxx>
> Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> ---
>
> Changes from v1:
> - printing a debug message when sink assert a error
>
> drivers/gpu/drm/i915/i915_reg.h | 1 +
> drivers/gpu/drm/i915/intel_psr.c | 24 +++++++++++++++++-------
> 2 files changed, 18 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h
> b/drivers/gpu/drm/i915/i915_reg.h
> index fb106026a1f4..d3efbd654889 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -4016,6 +4016,7 @@ enum {
> #define EDP_PSR_SKIP_AUX_EXIT (1<<12)
> #define EDP_PSR_TP1_TP2_SEL (0<<11)
> #define EDP_PSR_TP1_TP3_SEL (1<<11)
> +#define EDP_PSR_CRC_ENABLE (1<<10) /* BDW+
> */
> #define EDP_PSR_TP2_TP3_TIME_500us (0<<8)
> #define EDP_PSR_TP2_TP3_TIME_100us (1<<8)
> #define EDP_PSR_TP2_TP3_TIME_2500us (2<<8)
> diff --git a/drivers/gpu/drm/i915/intel_psr.c
> b/drivers/gpu/drm/i915/intel_psr.c
> index 558b08a43f9e..1920e7d03e06 100644
> --- a/drivers/gpu/drm/i915/intel_psr.c
> +++ b/drivers/gpu/drm/i915/intel_psr.c
> @@ -290,6 +290,8 @@ static void hsw_psr_enable_sink(struct intel_dp
> *intel_dp)
> dpcd_val |= DP_PSR_ENABLE_PSR2;
> if (dev_priv->psr.link_standby)
> dpcd_val |= DP_PSR_MAIN_LINK_ACTIVE;
> + if (!dev_priv->psr.psr2_enabled && INTEL_GEN(dev_priv) >= 8)
> + dpcd_val |= DP_PSR_CRC_VERIFICATION;
> drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG, dpcd_val);
>
> drm_dp_dpcd_writeb(&intel_dp->aux, DP_SET_POWER,
> DP_SET_POWER_D0);
> @@ -377,6 +379,9 @@ static void hsw_activate_psr1(struct intel_dp
> *intel_dp)
> else
> val |= EDP_PSR_TP1_TP2_SEL;
>
> + if (INTEL_GEN(dev_priv) >= 8)
> + val |= EDP_PSR_CRC_ENABLE;
> +
> val |= I915_READ(EDP_PSR_CTL) &
> EDP_PSR_RESTORE_PSR_ACTIVE_CTX_MASK;
> I915_WRITE(EDP_PSR_CTL, val);
> }
> @@ -602,10 +607,12 @@ static void hsw_psr_enable_source(struct
> intel_dp *intel_dp,
> * preventing other hw tracking issues now we can
> rely
> * on frontbuffer tracking.
> */
> - I915_WRITE(EDP_PSR_DEBUG,
> - EDP_PSR_DEBUG_MASK_MEMUP |
> - EDP_PSR_DEBUG_MASK_HPD |
> - EDP_PSR_DEBUG_MASK_LPSP);
> + u32 val = EDP_PSR_DEBUG_MASK_MEMUP |
> EDP_PSR_DEBUG_MASK_HPD
> + | EDP_PSR_DEBUG_MASK_LPSP;
> +
> + if (INTEL_GEN(dev_priv) >= 8)
> + val |= EDP_PSR_DEBUG_MASK_MAX_SLEEP;
> + I915_WRITE(EDP_PSR_DEBUG, val);
> }
> }
>
> @@ -1161,14 +1168,17 @@ void intel_psr_hpd_short_pulse_handle(struct
> intel_dp *intel_dp)
> goto dpcd_error;
> }
>
> - if (val & DP_PSR_RFB_STORAGE_ERROR) {
> - DRM_DEBUG_KMS("PSR RFB storage error, exiting
> PSR\n");
> + if (val & (DP_PSR_RFB_STORAGE_ERROR |
> DP_PSR_LINK_CRC_ERROR)) {
> + if (val & DP_PSR_RFB_STORAGE_ERROR)
> + DRM_DEBUG_KMS("PSR RFB storage error,
> exiting PSR\n");
> + if (val & DP_PSR_LINK_CRC_ERROR)
> + DRM_DEBUG_KMS("PSR Link CRC error, exiting
> PSR\n");
> intel_psr_exit(dev_priv);
Not sure how exit will help here.
We should print this as DRM_ERROR, check if CRC errors repeat more than
a few times and disable PSR altogether if they do. We can probably
start with a small threshold and then tune it.
Sorry for the delay in reviewing this patch.
> }
> /* clear status register */
> drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_ERROR_STATUS,
> val);
>
> - /* TODO: handle other PSR/PSR2 errors */
> + /* TODO: handle PSR2 errors */
> dpcd_error:
> intel_psr_schedule_activate_work(dev_priv);
> not_enabled:
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