Re: [Intel-gfx] [PATCH 1/3] drm/i915: Don't switch to TPS1 when disabling DP_TP_CTL

[Imre Deak]

On Tue, Feb 14, 2023 at 03:43:46PM +0200, Ville Syrjala wrote:
> From: Ville Syrjälä 
> 
> AFAICS Bspec has never asked us to switch to TPS1 when *disabling*
> DP_TP_CTL. Let's stop doing that in case it confuses something.
> We do have to switch before we *enable* DP_TP_CTL, but that
> is already being handled correctly.
> 
> Signed-off-by: Ville Syrjälä 

Reviewed-by: Imre Deak 

> ---
>  drivers/gpu/drm/i915/display/intel_ddi.c | 6 ++
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c 
> b/drivers/gpu/drm/i915/display/intel_ddi.c
> index bfd1e30a27b4..4af2ba2dfcad 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -2624,8 +2624,7 @@ static void intel_disable_ddi_buf(struct intel_encoder 
> *encoder,
>  
>   if (intel_crtc_has_dp_encoder(crtc_state)) {
>   val = intel_de_read(dev_priv, dp_tp_ctl_reg(encoder, 
> crtc_state));
> - val &= ~(DP_TP_CTL_ENABLE | DP_TP_CTL_LINK_TRAIN_MASK);
> - val |= DP_TP_CTL_LINK_TRAIN_PAT1;
> + val &= ~DP_TP_CTL_ENABLE;
>   intel_de_write(dev_priv, dp_tp_ctl_reg(encoder, crtc_state), 
> val);
>   }
>  
> @@ -3153,8 +3152,7 @@ static void intel_ddi_prepare_link_retrain(struct 
> intel_dp *intel_dp,
>   wait = true;
>   }
>  
> - dp_tp_ctl &= ~(DP_TP_CTL_ENABLE | DP_TP_CTL_LINK_TRAIN_MASK);
> - dp_tp_ctl |= DP_TP_CTL_LINK_TRAIN_PAT1;
> + dp_tp_ctl &= ~DP_TP_CTL_ENABLE;
>   intel_de_write(dev_priv, dp_tp_ctl_reg(encoder, crtc_state), 
> dp_tp_ctl);
>   intel_de_posting_read(dev_priv, dp_tp_ctl_reg(encoder, 
> crtc_state));
>  
> -- 
> 2.39.1
> 

[Intel-gfx] [PATCH 1/3] drm/i915: Don't switch to TPS1 when disabling DP_TP_CTL

[Ville Syrjala]

From: Ville Syrjälä 

AFAICS Bspec has never asked us to switch to TPS1 when *disabling*
DP_TP_CTL. Let's stop doing that in case it confuses something.
We do have to switch before we *enable* DP_TP_CTL, but that
is already being handled correctly.

Signed-off-by: Ville Syrjälä 
---
 drivers/gpu/drm/i915/display/intel_ddi.c | 6 ++
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c 
b/drivers/gpu/drm/i915/display/intel_ddi.c
index bfd1e30a27b4..4af2ba2dfcad 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -2624,8 +2624,7 @@ static void intel_disable_ddi_buf(struct intel_encoder 
*encoder,
 
if (intel_crtc_has_dp_encoder(crtc_state)) {
val = intel_de_read(dev_priv, dp_tp_ctl_reg(encoder, 
crtc_state));
-   val &= ~(DP_TP_CTL_ENABLE | DP_TP_CTL_LINK_TRAIN_MASK);
-   val |= DP_TP_CTL_LINK_TRAIN_PAT1;
+   val &= ~DP_TP_CTL_ENABLE;
intel_de_write(dev_priv, dp_tp_ctl_reg(encoder, crtc_state), 
val);
}
 
@@ -3153,8 +3152,7 @@ static void intel_ddi_prepare_link_retrain(struct 
intel_dp *intel_dp,
wait = true;
}
 
-   dp_tp_ctl &= ~(DP_TP_CTL_ENABLE | DP_TP_CTL_LINK_TRAIN_MASK);
-   dp_tp_ctl |= DP_TP_CTL_LINK_TRAIN_PAT1;
+   dp_tp_ctl &= ~DP_TP_CTL_ENABLE;
intel_de_write(dev_priv, dp_tp_ctl_reg(encoder, crtc_state), 
dp_tp_ctl);
intel_de_posting_read(dev_priv, dp_tp_ctl_reg(encoder, 
crtc_state));
 
-- 
2.39.1