diff mbox series

[6/6] drm/i915/mtl: Add DP FEC BS jitter WA

Message ID 20240129175533.904590-7-imre.deak@intel.com (mailing list archive)
State New, archived
Headers show
Series drm/i915/dp: Add jitter WAs for MST/FEC/DSC links | expand

Commit Message

Imre Deak Jan. 29, 2024, 5:55 p.m. UTC
Add a workaround to fix BS (blank start) to BS jitter fixes on non-UHBR
MST/FEC and UHBR links. Bspec doesn't provide an actual WA ID for this.

Bspec: 65448, 50054

Signed-off-by: Imre Deak <imre.deak@intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c | 3 +++
 drivers/gpu/drm/i915/i915_reg.h              | 1 +
 2 files changed, 4 insertions(+)

Comments

Nautiyal, Ankit K Jan. 31, 2024, 6:04 a.m. UTC | #1
On 1/29/2024 11:25 PM, Imre Deak wrote:
> Add a workaround to fix BS (blank start) to BS jitter fixes on non-UHBR
> MST/FEC and UHBR links. Bspec doesn't provide an actual WA ID for this.
>
> Bspec: 65448, 50054
>
> Signed-off-by: Imre Deak <imre.deak@intel.com>
> ---
>   drivers/gpu/drm/i915/display/intel_display.c | 3 +++
>   drivers/gpu/drm/i915/i915_reg.h              | 1 +
>   2 files changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index e0b75aa18ae33..72a852cccd3f3 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -432,6 +432,9 @@ void intel_enable_transcoder(const struct intel_crtc_state *new_crtc_state)
>   		u32 clear = DP_DSC_INSERT_SF_AT_EOL_WA;
>   		u32 set = 0;
>   
> +		if (DISPLAY_VER(dev_priv) == 14)
> +			set |= DP_FEC_BS_JITTER_WA;
> +
>   		intel_de_rmw(dev_priv,
>   			     hsw_chicken_trans_reg(dev_priv, cpu_transcoder),
>   			     clear, set);
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 9873daa16c6a1..d86e904ffe893 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -4619,6 +4619,7 @@
>   #define   DDIE_TRAINING_OVERRIDE_ENABLE	REG_BIT(17) /* CHICKEN_TRANS_A only */
>   #define   DDIE_TRAINING_OVERRIDE_VALUE	REG_BIT(16) /* CHICKEN_TRANS_A only */
>   #define   PSR2_ADD_VERTICAL_LINE_COUNT	REG_BIT(15)
> +#define   DP_FEC_BS_JITTER_WA		REG_BIT(15)

Was wondering if this is for MTL+, but it seems this is required only 
for MTL.

Patch LGTM.

Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>

>   #define   PSR2_VSC_ENABLE_PROG_HEADER	REG_BIT(12)
>   #define   DP_DSC_INSERT_SF_AT_EOL_WA	REG_BIT(4)
>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index e0b75aa18ae33..72a852cccd3f3 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -432,6 +432,9 @@  void intel_enable_transcoder(const struct intel_crtc_state *new_crtc_state)
 		u32 clear = DP_DSC_INSERT_SF_AT_EOL_WA;
 		u32 set = 0;
 
+		if (DISPLAY_VER(dev_priv) == 14)
+			set |= DP_FEC_BS_JITTER_WA;
+
 		intel_de_rmw(dev_priv,
 			     hsw_chicken_trans_reg(dev_priv, cpu_transcoder),
 			     clear, set);
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 9873daa16c6a1..d86e904ffe893 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -4619,6 +4619,7 @@ 
 #define   DDIE_TRAINING_OVERRIDE_ENABLE	REG_BIT(17) /* CHICKEN_TRANS_A only */
 #define   DDIE_TRAINING_OVERRIDE_VALUE	REG_BIT(16) /* CHICKEN_TRANS_A only */
 #define   PSR2_ADD_VERTICAL_LINE_COUNT	REG_BIT(15)
+#define   DP_FEC_BS_JITTER_WA		REG_BIT(15)
 #define   PSR2_VSC_ENABLE_PROG_HEADER	REG_BIT(12)
 #define   DP_DSC_INSERT_SF_AT_EOL_WA	REG_BIT(4)