Re: [PATCH v9 4/7] drm/i915/tgl: Do modeset to enable and configure DC3CO exitline

Imre Deak
2019-09-27T15:10:35Z

On Thu, Sep 26, 2019 at 08:26:18PM +0530, Anshuman Gupta wrote:
> DC3CO enabling B.Specs sequence requires to enable end configure
> exit scanlines to TRANS_EXITLINE register, programming this register
> has to be part of modeset sequence as this can't be change when
> transcoder or port is enabled.
> When system boots with only eDP panel there may not be real
> modeset as BIOS has already programmed the necessary registers,
> therefore it needs to force a modeset to enable and configure
> DC3CO exitline.
>
> v1: Computing dc3co_exitline crtc state from a DP encoder
> compute config. [Imre]
> Enabling and disabling DC3CO PSR2 transcoder exitline from
> encoder pre_enable and post_disable hooks. [Imre]
> Computing dc3co_exitline instead of has_dc3co_exitline bool. [Imre]
>
> Cc: Jani Nikula <jani.nikula@intel.com>
> Cc: Imre Deak <imre.deak@intel.com>
> Cc: Animesh Manna <animesh.manna@intel.com>
> Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_ddi.c | 7 ++
> drivers/gpu/drm/i915/display/intel_display.c | 1 +
> .../drm/i915/display/intel_display_power.c | 87 +++++++++++++++++++
> .../drm/i915/display/intel_display_power.h | 8 ++
> .../drm/i915/display/intel_display_types.h | 1 +
> drivers/gpu/drm/i915/display/intel_dp.c | 2 +
> 6 files changed, 106 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index aa470c70a198..e0e276909e76 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -3212,6 +3212,8 @@ static void tgl_ddi_pre_enable_dp(struct intel_encoder *encoder,
> int level = intel_ddi_dp_level(intel_dp);
> enum transcoder transcoder = crtc_state->cpu_transcoder;
>
> + /* Program the dc3co psr2 transcoder exitline */
> + tgl_set_psr2_transcoder_exitline(crtc_state);
> intel_dp_set_link_params(intel_dp, crtc_state->port_clock,
> crtc_state->lane_count, is_mst);
>
> @@ -3524,6 +3526,8 @@ static void intel_ddi_post_disable_dp(struct intel_encoder *encoder,
> dig_port->ddi_io_power_domain);
>
> intel_ddi_clk_disable(encoder);
> + /* Disable the dc3co psr2 transcoder exitline */
> + tgl_clear_psr2_transcoder_exitline(old_crtc_state);
> }
>
> static void intel_ddi_post_disable_hdmi(struct intel_encoder *encoder,
> @@ -4070,6 +4074,9 @@ void intel_ddi_get_config(struct intel_encoder *encoder,
> break;
> }
>
> + if (encoder->type == INTEL_OUTPUT_EDP)
> + tgl_dc3co_exitline_get_config(pipe_config);
> +
> pipe_config->has_audio =
> intel_ddi_is_audio_enabled(dev_priv, cpu_transcoder);
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 8f125f1624bd..a467c7523e06 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -12820,6 +12820,7 @@ intel_pipe_config_compare(const struct intel_crtc_state *current_config,
>
> PIPE_CONF_CHECK_I(pixel_multiplier);
> PIPE_CONF_CHECK_I(output_format);
> + PIPE_CONF_CHECK_I(dc3co_exitline);
> PIPE_CONF_CHECK_BOOL(has_hdmi_sink);
> if ((INTEL_GEN(dev_priv) < 8 && !IS_HASWELL(dev_priv)) ||
> IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c
> index 9f787556f80d..84e4cfd95b43 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_power.c
> @@ -19,6 +19,7 @@
> #include "intel_hotplug.h"
> #include "intel_sideband.h"
> #include "intel_tc.h"
> +#include "intel_pm.h"
>
> bool intel_display_power_well_is_enabled(struct drm_i915_private *dev_priv,
> enum i915_power_well_id power_well_id);
> @@ -785,6 +786,92 @@ static void gen9_set_dc_state(struct drm_i915_private *dev_priv, u32 state)
> dev_priv->csr.dc_state = val & mask;
> }
>
> +void tgl_clear_psr2_transcoder_exitline(const struct intel_crtc_state *cstate)
> +{
> + struct drm_i915_private *dev_priv = to_i915(cstate->base.crtc->dev);
> + u32 val;
> +
> + if (!cstate->dc3co_exitline)
> + return;
> +
> + val = I915_READ(EXITLINE(cstate->cpu_transcoder));
> + val &= ~(EXITLINE_MASK | EXITLINE_ENABLE);
> + I915_WRITE(EXITLINE(cstate->cpu_transcoder), val);
> +}
> +
> +void tgl_set_psr2_transcoder_exitline(const struct intel_crtc_state *cstate)
> +{
> + u32 val, exit_scanlines;
> + struct drm_i915_private *dev_priv = to_i915(cstate->base.crtc->dev);
> +
> + if (!cstate->dc3co_exitline)
> + return;
> +
> + exit_scanlines = cstate->dc3co_exitline;
> + exit_scanlines <<= EXITLINE_SHIFT;
> + val = I915_READ(EXITLINE(cstate->cpu_transcoder));
> + val &= ~(EXITLINE_MASK | EXITLINE_ENABLE);
> + val |= exit_scanlines;
> + val |= EXITLINE_ENABLE;
> + I915_WRITE(EXITLINE(cstate->cpu_transcoder), val);
> +}
> +
> +/*
> + * DC3CO requires to enable exitline and program DC3CO requires
> + * exit scanlines to TRANS_EXITLINE register, which should only
> + * change before transcoder or port are enabled.
> + * This requires to disable the fastset at boot for eDP output.
> + */
> +void tgl_dc3co_exitline_compute_config(struct intel_encoder *encoder,
> + struct intel_crtc_state *cstate)
> +{
> + u32 exit_scanlines;
> + struct drm_i915_private *dev_priv = to_i915(cstate->base.crtc->dev);
> + u32 crtc_vdisplay = cstate->base.adjusted_mode.crtc_vdisplay;
> +
> + if (!IS_TIGERLAKE(dev_priv))
> + return;

This should match the corresponding check in get_allowed_dc_mask(),
where it's GEN>=12. The check is also redundant then here, since below we
check allowed_dc_mask.
> +
> + if (!(dev_priv->csr.allowed_dc_mask & DC_STATE_EN_DC3CO))
> + return;
> +
> + /* B.Specs:49196 DC3CO only works with pipeA and DDIA.*/
> + if (encoder->port != PORT_A)

What about the pipe A restriction?

> + return;
> +
> + if (!cstate->has_psr2 || !cstate->base.active)

Let's clear cstate->dc3co_exitline in this case explicitly. Currently
not doing this only works for backwards compatibility, see
clear_intel_crtc_state().

> + return;
> +
> + /*
> + * DC3CO Exit time 200us B.Spec 49196
> + * PSR2 transcoder Early Exit scanlines = ROUNDUP(200 / line time) + 1
> + */
> + exit_scanlines =
> + intel_usecs_to_scanlines(&cstate->base.adjusted_mode, 200) + 1;
> +
> + if (WARN_ON(exit_scanlines > crtc_vdisplay))
> + return;
> +
> + cstate->dc3co_exitline = crtc_vdisplay - exit_scanlines;
> +}
> +
> +void tgl_dc3co_exitline_get_config(struct intel_crtc_state *crtc_state)
> +{
> + u32 val;
> + struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev);
> +
> + if (!IS_TIGERLAKE(dev_priv))
> + return;

As mentioned above, this should match the check in
get_allowed_dc_mask().

> +
> + if (!(dev_priv->csr.allowed_dc_mask & DC_STATE_EN_DC3CO))
> + return;

We also want to read this out if the user has disabled DC3co.
compute_config() will make sure that we won't enable if then.

> +
> + val = I915_READ(EXITLINE(crtc_state->cpu_transcoder));
> +
> + if (val & EXITLINE_ENABLE)
> + crtc_state->dc3co_exitline = val & EXITLINE_MASK;
> +}

There is no good reason to have any of these funcs above in
display_power.c exported, so let's just move them where they are used
(intel_ddi.c).

> +
> static void
> allowed_dc_mask_to_target_dc_state(struct drm_i915_private *dev_priv)
> {
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.h b/drivers/gpu/drm/i915/display/intel_display_power.h
> index 13fc705799fd..4e76f93bbee5 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_power.h
> @@ -8,10 +8,13 @@
>
> #include "intel_display.h"
> #include "intel_runtime_pm.h"
> +#include "intel_sprite.h"
> #include "i915_reg.h"
>
> struct drm_i915_private;
> struct intel_encoder;
> +struct intel_crtc_state;
> +struct intel_atomic_state;
>
> enum intel_display_power_domain {
> POWER_DOMAIN_DISPLAY_CORE,
> @@ -258,6 +261,11 @@ void intel_display_power_resume_early(struct drm_i915_private *i915);
> void intel_display_power_suspend(struct drm_i915_private *i915);
> void intel_display_power_resume(struct drm_i915_private *i915);
> void tgl_set_target_dc_state(struct drm_i915_private *dev_priv, u32 state);
> +void tgl_dc3co_exitline_compute_config(struct intel_encoder *encoder,
> + struct intel_crtc_state *crtc_state);
> +void tgl_dc3co_exitline_get_config(struct intel_crtc_state *crtc_state);
> +void tgl_clear_psr2_transcoder_exitline(const struct intel_crtc_state *state);
> +void tgl_set_psr2_transcoder_exitline(const struct intel_crtc_state *state);
>
> const char *
> intel_display_power_domain_str(enum intel_display_power_domain domain);
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 976669f01a8c..8aa38ace7845 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -870,6 +870,7 @@ struct intel_crtc_state {
>
> bool has_psr;
> bool has_psr2;
> + u32 dc3co_exitline;
>
> /*
> * Frequence the dpll for the port should run at. Differs from the
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 2b1e71f992b0..77dd29627610 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -2368,6 +2368,8 @@ intel_dp_compute_config(struct intel_encoder *encoder,
>
> intel_psr_compute_config(intel_dp, pipe_config);
>
> + tgl_dc3co_exitline_compute_config(encoder, pipe_config);
> +

The steps in compute_config hook should have a corresponding step in the
get_config hook, so let's do this readout in intel_ddi_compute_config()
instead.

> intel_hdcp_transcoder_config(intel_connector,
> pipe_config->cpu_transcoder);
>
> --
> 2.21.0
>