Re: [PATCH v15 8/9] drm/i915/display: Compute vrr_vsync params

["Nautiyal, Ankit K" <ankit.k.nautiyal@intel.com>]

On 3/1/2024 2:15 PM, Mitul Golani wrote:
> Compute vrr_vsync_start/end, which sets the position
> for hardware to send the Vsync at a fixed position
> relative to the end of the Vblank.
>
> --v2:
> - Updated VSYNC_START/END macros to VRR_VSYNC_START/END. (Ankit)
> - Updated bit fields of VRR_VSYNC_START/END. (Ankit)
>
> --v3:
> - Add PIPE_CONF_CHECK_I(vrr.vsync_start/end).
> - Read/write vrr_vsync params only when we intend to send
> adaptive_sync sdp.
>
> Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
> ---
>   drivers/gpu/drm/i915/display/intel_display.c  |  2 ++
>   .../drm/i915/display/intel_display_types.h    |  1 +
>   drivers/gpu/drm/i915/display/intel_vrr.c      | 29 +++++++++++++++++--
>   drivers/gpu/drm/i915/i915_reg.h               |  7 +++++
>   4 files changed, 37 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 88158f06bf82..f62c3ae7f0fd 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -5377,6 +5377,8 @@ intel_pipe_config_compare(const struct intel_crtc_state *current_config,
>   		PIPE_CONF_CHECK_I(vrr.flipline);
>   		PIPE_CONF_CHECK_I(vrr.pipeline_full);
>   		PIPE_CONF_CHECK_I(vrr.guardband);
> +		PIPE_CONF_CHECK_I(vrr.vsync_start);
> +		PIPE_CONF_CHECK_I(vrr.vsync_end);
>   	}
>   
>   #undef PIPE_CONF_CHECK_X
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 098957cea25b..e8ba3c077569 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -1423,6 +1423,7 @@ struct intel_crtc_state {
>   		bool enable, in_range;
>   		u8 pipeline_full;
>   		u16 flipline, vmin, vmax, guardband;
> +		u32 vsync_end, vsync_start;
>   	} vrr;
>   
>   	/* Stream Splitter for eDP MSO */
> diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c b/drivers/gpu/drm/i915/display/intel_vrr.c
> index 5d905f932cb4..d24a42902e69 100644
> --- a/drivers/gpu/drm/i915/display/intel_vrr.c
> +++ b/drivers/gpu/drm/i915/display/intel_vrr.c
> @@ -9,6 +9,7 @@
>   #include "intel_de.h"
>   #include "intel_display_types.h"
>   #include "intel_vrr.h"
> +#include "intel_dp.h"
>   
>   bool intel_vrr_is_capable(struct intel_connector *connector)
>   {
> @@ -113,6 +114,7 @@ intel_vrr_compute_config(struct intel_crtc_state *crtc_state,
>   	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
>   	struct intel_connector *connector =
>   		to_intel_connector(conn_state->connector);
> +	struct intel_dp *intel_dp = intel_attached_dp(connector);
>   	struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
>   	const struct drm_display_info *info = &connector->base.display_info;
>   	int vmin, vmax;
> @@ -165,6 +167,15 @@ intel_vrr_compute_config(struct intel_crtc_state *crtc_state,
>   	if (crtc_state->uapi.vrr_enabled) {
>   		crtc_state->vrr.enable = true;
>   		crtc_state->mode_flags |= I915_MODE_FLAG_VRR;
> +
> +		if (intel_dp_as_sdp_supported(intel_dp)) {
> +			crtc_state->vrr.vsync_start =
> +				(crtc_state->hw.adjusted_mode.crtc_vtotal -
> +				VRR_VSYNC_START(crtc_state->hw.adjusted_mode.vsync_start));
> +			crtc_state->vrr.vsync_end =
> +				(crtc_state->hw.adjusted_mode.crtc_vtotal -
> +				(VRR_VSYNC_END(crtc_state->hw.adjusted_mode.vsync_end) >> 16));

I think you are using the VRR_SYNC_START/END macros incorrectly.

We dont need to use these macros here.

> +		}
>   	}
>   }
>   
> @@ -203,6 +214,10 @@ void intel_vrr_set_transcoder_timings(const struct intel_crtc_state *crtc_state)
>   	intel_de_write(dev_priv, TRANS_VRR_VMAX(cpu_transcoder), crtc_state->vrr.vmax - 1);
>   	intel_de_write(dev_priv, TRANS_VRR_CTL(cpu_transcoder), trans_vrr_ctl(crtc_state));
>   	intel_de_write(dev_priv, TRANS_VRR_FLIPLINE(cpu_transcoder), crtc_state->vrr.flipline - 1);
> +
> +	if (crtc_state->vrr.vsync_end && crtc_state->vrr.vsync_start)
> +		intel_de_write(dev_priv, TRANS_VRR_VSYNC(cpu_transcoder),
> +			       crtc_state->vrr.vsync_end << 16 | crtc_state->vrr.vsync_start);

Here is where the macros should be used.

VRR_SYNC_END(crtc_state->vrr.vsync_end) | 
VRR_SYNC_START(crtc_state->vrr.vsync_start);


>   }
>   
>   void intel_vrr_send_push(const struct intel_crtc_state *crtc_state)
> @@ -263,7 +278,7 @@ void intel_vrr_get_config(struct intel_crtc_state *crtc_state)
>   {
>   	struct drm_i915_private *dev_priv = to_i915(crtc_state->uapi.crtc->dev);
>   	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
> -	u32 trans_vrr_ctl;
> +	u32 trans_vrr_ctl, trans_vrr_vsync;
>   
>   	trans_vrr_ctl = intel_de_read(dev_priv, TRANS_VRR_CTL(cpu_transcoder));
>   
> @@ -283,6 +298,16 @@ void intel_vrr_get_config(struct intel_crtc_state *crtc_state)
>   		crtc_state->vrr.vmin = intel_de_read(dev_priv, TRANS_VRR_VMIN(cpu_transcoder)) + 1;
>   	}
>   
> -	if (crtc_state->vrr.enable)
> +	if (crtc_state->vrr.enable) {
>   		crtc_state->mode_flags |= I915_MODE_FLAG_VRR;
> +
> +		if (HAS_AS_SDP(dev_priv)) {
> +			trans_vrr_vsync =
> +				intel_de_read(dev_priv, TRANS_VRR_VSYNC(cpu_transcoder));
> +			crtc_state->vrr.vsync_start =
> +				trans_vrr_vsync & VRR_VSYNC_START_MASK;
> +			crtc_state->vrr.vsync_end =
> +				trans_vrr_vsync & VRR_VSYNC_START_MASK;

Here too you should use REG_FIELD_GET(VRR_VSYNC_START/END_MASK, 
trans_vrr_vsync) to fill crtc_state->vrr.sync_start/end.

Regards,

Ankit


> +		}
> +	}
>   }
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index dce276236707..53d8eb7ea1ea 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -2007,7 +2007,9 @@
>   #define _TRANS_VRR_CTL_B		0x61420
>   #define _TRANS_VRR_CTL_C		0x62420
>   #define _TRANS_VRR_CTL_D		0x63420
> +#define _TRANS_VRR_VSYNC_A		0x60078
>   #define TRANS_VRR_CTL(trans)			_MMIO_TRANS2(trans, _TRANS_VRR_CTL_A)
> +#define TRANS_VRR_VSYNC(trans)			_MMIO_TRANS2(trans, _TRANS_VRR_VSYNC_A)
>   #define   VRR_CTL_VRR_ENABLE			REG_BIT(31)
>   #define   VRR_CTL_IGN_MAX_SHIFT			REG_BIT(30)
>   #define   VRR_CTL_FLIP_LINE_EN			REG_BIT(29)
> @@ -2087,6 +2089,11 @@
>   #define TRANS_VRR_STATUS2(trans)	_MMIO_TRANS2(trans, _TRANS_VRR_STATUS2_A)
>   #define   VRR_STATUS2_VERT_LN_CNT_MASK	REG_GENMASK(19, 0)
>   
> +#define   VRR_VSYNC_END_MASK		REG_GENMASK(28, 16)
> +#define   VRR_VSYNC_END(vsync_end)	REG_FIELD_PREP(VSYNC_END_MASK, (vsync_end))
> +#define   VRR_VSYNC_START_MASK		REG_GENMASK(12, 0)
> +#define   VRR_VSYNC_START(vsync_start)	REG_FIELD_PREP(VSYNC_START_MASK, (vsync_start))
> +
>   #define _TRANS_PUSH_A			0x60A70
>   #define _TRANS_PUSH_B			0x61A70
>   #define _TRANS_PUSH_C			0x62A70