[PATCH v8 3/7] drm/i915: Compute CMRR and calculate vtotal
Nautiyal, Ankit K
ankit.k.nautiyal at intel.com
Thu May 23 11:21:35 UTC 2024
On 5/9/2024 1:28 PM, Mitul Golani wrote:
> Compute Fixed Average Vtotal/CMRR with resepect to
> userspace VRR enablement. Also calculate required
> parameters in case of CMRR is enabled. During
> intel_vrr_compute_config, CMRR is getting enabled
> based on userspace has enabled Adaptive Sync Vtotal
> mode (Legacy VRR) or not. Make CMRR as small subset of
As I understand what you mean is Variable refresh mode with VRR timing
generator or)VRR framework)
Lets not use legacy VRR term. This will create confusion with legacy
timing generator.
> FAVT mode, when Panle is running on Fixed refresh rate
typo : panel
> and on VRR framework then only enable CMRR to match with
> actual refresh rate.
>
> --v2:
> - Update is_cmrr_frac_required function return as bool, not int. [Jani]
> - Use signed int math instead of unsigned in cmrr_get_vtotal2. [Jani]
> - Fix typo and usage of camel case in cmrr_get_vtotal. [Jani]
> - Use do_div in cmrr_get_vtotalwhile calculating cmrr_m. [ Jani]
> - Simplify cmrr and vrr compute config in intel_vrr_compute_config. [Jani]
> - Correct valiable name usage in is_cmrr_frac_required. [Ville]
>
> --v3:
> - Removing RFC tag.
>
> --v4:
> - Added edp check to address edp usecase for now. (ville)
> - Updated is_cmrr_fraction_required to more simplified calculation.
> - on longterm goal to be worked upon uapi as suggestion from ville.
>
> --v5:
> - Correct vtotal paramas accuracy and add 2 digit precision.
> - Avoid using DIV_ROUND_UP and improve scanline precision.
>
> --v6:
> - Make CMRR a small subset of FAVT mode.
>
> Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani at intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_display.c | 1 +
> .../drm/i915/display/intel_display_device.h | 1 +
> drivers/gpu/drm/i915/display/intel_vrr.c | 99 ++++++++++++++++---
> 3 files changed, 89 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 4a5318ab017d..8a76db59c85f 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -5458,6 +5458,7 @@ intel_pipe_config_compare(const struct intel_crtc_state *current_config,
> PIPE_CONF_CHECK_I(vrr.vsync_end);
> PIPE_CONF_CHECK_LLI(cmrr.cmrr_m);
> PIPE_CONF_CHECK_LLI(cmrr.cmrr_n);
> + PIPE_CONF_CHECK_BOOL(cmrr.enable);
> }
>
> #undef PIPE_CONF_CHECK_X
> diff --git a/drivers/gpu/drm/i915/display/intel_display_device.h b/drivers/gpu/drm/i915/display/intel_display_device.h
> index 17ddf82f0b6e..b372b1acc19b 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_device.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_device.h
> @@ -71,6 +71,7 @@ struct drm_printer;
> BIT(trans)) != 0)
> #define HAS_VRR(i915) (DISPLAY_VER(i915) >= 11)
> #define HAS_AS_SDP(i915) (DISPLAY_VER(i915) >= 13)
> +#define HAS_CMRR(i915) (DISPLAY_VER(i915) >= 20)
> #define INTEL_NUM_PIPES(i915) (hweight8(DISPLAY_RUNTIME_INFO(i915)->pipe_mask))
> #define I915_HAS_HOTPLUG(i915) (DISPLAY_INFO(i915)->has_hotplug)
> #define OVERLAY_NEEDS_PHYSICAL(i915) (DISPLAY_INFO(i915)->overlay_needs_physical)
> diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c b/drivers/gpu/drm/i915/display/intel_vrr.c
> index 83ae56d22b5f..f5ba87fa00fe 100644
> --- a/drivers/gpu/drm/i915/display/intel_vrr.c
> +++ b/drivers/gpu/drm/i915/display/intel_vrr.c
> @@ -11,6 +11,9 @@
> #include "intel_vrr.h"
> #include "intel_dp.h"
>
> +#define FIXED_POINT_PRECISION 100
> +#define CMRR_PRECISION_TOLERANCE 10
> +
> bool intel_vrr_is_capable(struct intel_connector *connector)
> {
> const struct drm_display_info *info = &connector->base.display_info;
> @@ -106,6 +109,59 @@ int intel_vrr_vmax_vblank_start(const struct intel_crtc_state *crtc_state)
> return crtc_state->vrr.vmax - intel_vrr_vblank_exit_length(crtc_state);
> }
>
> +static bool
> +is_cmrr_frac_required(struct intel_crtc_state *crtc_state, bool is_edp)
> +{
> + int calculated_refresh_k, actual_refresh_k, pixel_clock_per_line;
> + struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
> + struct drm_i915_private *i915 = to_i915(crtc_state->uapi.crtc->dev);
> +
> + if (!(HAS_CMRR(i915) && is_edp))
> + return false;
> +
> + actual_refresh_k =
> + drm_mode_vrefresh(adjusted_mode) * FIXED_POINT_PRECISION;
> + pixel_clock_per_line =
> + adjusted_mode->crtc_clock * 1000 / adjusted_mode->crtc_htotal;
> + calculated_refresh_k =
> + pixel_clock_per_line * FIXED_POINT_PRECISION / adjusted_mode->crtc_vtotal;
> +
> + if ((actual_refresh_k - calculated_refresh_k) < CMRR_PRECISION_TOLERANCE)
> + return false;
> +
> + return true;
> +}
> +
> +static unsigned int
> +cmrr_get_vtotal(struct intel_crtc_state *crtc_state)
> +{
> + int multiplier_m = 1, multiplier_n = 1, vtotal;
> + int actual_refresh_rate, desired_refresh_rate;
> + long long actual_pixel_rate, adjusted_pixel_rate, pixel_clock_per_line;
> + struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
> +
> + pixel_clock_per_line =
> + adjusted_mode->crtc_clock * 1000 / adjusted_mode->crtc_htotal;
> + actual_refresh_rate =
> + pixel_clock_per_line * FIXED_POINT_PRECISION / adjusted_mode->crtc_vtotal;
> + desired_refresh_rate = drm_mode_vrefresh(adjusted_mode);
> + actual_pixel_rate = actual_refresh_rate * adjusted_mode->crtc_vtotal;
> + actual_pixel_rate =
> + (actual_pixel_rate * adjusted_mode->crtc_htotal) / FIXED_POINT_PRECISION;
> +
> + multiplier_m = 1001;
> + multiplier_n = 1000;
> +
> + crtc_state->cmrr.cmrr_n =
> + ((desired_refresh_rate * adjusted_mode->crtc_htotal * multiplier_n) / multiplier_m);
> + crtc_state->cmrr.cmrr_n *= multiplier_n;
> + vtotal = (actual_pixel_rate * multiplier_n) / crtc_state->cmrr.cmrr_n;
> + adjusted_pixel_rate = actual_pixel_rate * multiplier_m;
> + crtc_state->cmrr.cmrr_m = do_div(adjusted_pixel_rate, crtc_state->cmrr.cmrr_n);
> +
> + return vtotal;
> +}
> +
> void
> intel_vrr_compute_config(struct intel_crtc_state *crtc_state,
> struct drm_connector_state *conn_state)
> @@ -115,6 +171,7 @@ intel_vrr_compute_config(struct intel_crtc_state *crtc_state,
> struct intel_connector *connector =
> to_intel_connector(conn_state->connector);
> struct intel_dp *intel_dp = intel_attached_dp(connector);
> + bool is_edp = intel_dp_is_edp(intel_dp);
> struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
> const struct drm_display_info *info = &connector->base.display_info;
> int vmin, vmax;
> @@ -159,18 +216,10 @@ intel_vrr_compute_config(struct intel_crtc_state *crtc_state,
> crtc_state->vrr.flipline = crtc_state->vrr.vmin + 1;
>
> /*
> - * For XE_LPD+, we use guardband and pipeline override
> - * is deprecated.
> + * When panel is VRR capable and userspace has
> + * not enabled adaptive sync mode then Fixed Average
> + * Vtotal mode should be enabled.
> */
> - if (DISPLAY_VER(i915) >= 13) {
> - crtc_state->vrr.guardband =
> - crtc_state->vrr.vmin + 1 - adjusted_mode->crtc_vblank_start;
> - } else {
> - crtc_state->vrr.pipeline_full =
> - min(255, crtc_state->vrr.vmin - adjusted_mode->crtc_vblank_start -
> - crtc_state->framestart_delay - 1);
> - }
> -
> if (crtc_state->uapi.vrr_enabled) {
> crtc_state->vrr.enable = true;
> crtc_state->mode_flags |= I915_MODE_FLAG_VRR;
> @@ -182,6 +231,25 @@ intel_vrr_compute_config(struct intel_crtc_state *crtc_state,
> (crtc_state->hw.adjusted_mode.crtc_vtotal -
> crtc_state->hw.adjusted_mode.vsync_end);
> }
> + } else if (is_cmrr_frac_required(crtc_state, is_edp)) {
> + crtc_state->cmrr.enable = true;
Can we have vrr.enable = true, to mean that VRR timing generator is
enabled and (false meaning legacy timing generator is enabled)
In that case, cmrr.enable flag can be a special case where VRR timing
generator is used for Fixed average vtotal mode.
This will help later when we will gradually move from legacy timing
generator to VRR timing generator.
So with cmrr.enable set vrr.enable will still be set. IMHO this will
also reduce the change to vrr_enabling/disabling in Patch#2.
Regards,
Ankit
> + crtc_state->vrr.vmax = cmrr_get_vtotal(crtc_state);
> + crtc_state->vrr.vmin = crtc_state->vrr.vmax;
> + crtc_state->vrr.flipline = crtc_state->vrr.vmin;
> + crtc_state->mode_flags |= I915_MODE_FLAG_VRR;
> + }
> +
> + /*
> + * For XE_LPD+, we use guardband and pipeline override
> + * is deprecated.
> + */
> + if (DISPLAY_VER(i915) >= 13) {
> + crtc_state->vrr.guardband =
> + crtc_state->vrr.vmin + 1 - adjusted_mode->crtc_vblank_start;
> + } else {
> + crtc_state->vrr.pipeline_full =
> + min(255, crtc_state->vrr.vmin - adjusted_mode->crtc_vblank_start -
> + crtc_state->framestart_delay - 1);
> }
> }
>
> @@ -317,7 +385,14 @@ void intel_vrr_get_config(struct intel_crtc_state *crtc_state)
>
> trans_vrr_ctl = intel_de_read(dev_priv, TRANS_VRR_CTL(cpu_transcoder));
>
> - crtc_state->vrr.enable = trans_vrr_ctl & VRR_CTL_VRR_ENABLE;
> + if (HAS_CMRR(dev_priv)) {
> + crtc_state->cmrr.enable = (trans_vrr_ctl & VRR_CTL_CMRR_ENABLE) &&
> + (trans_vrr_ctl & VRR_CTL_VRR_ENABLE);
> + crtc_state->vrr.enable = trans_vrr_ctl & VRR_CTL_VRR_ENABLE &&
> + !(trans_vrr_ctl & VRR_CTL_CMRR_ENABLE);
> + } else {
> + crtc_state->vrr.enable = trans_vrr_ctl & VRR_CTL_VRR_ENABLE;
> + }
>
> if (crtc_state->cmrr.enable) {
> crtc_state->cmrr.cmrr_n =
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