[Intel-gfx] [PATCH 3/6] drm/i915: Add support for DRRS to switch RR
Jani Nikula
jani.nikula at linux.intel.com
Wed Mar 26 13:55:16 CET 2014
On Fri, 07 Mar 2014, Vandana Kannan <vandana.kannan at intel.com> wrote:
> From: Pradeep Bhat <pradeep.bhat at intel.com>
>
> This patch computes and stored 2nd M/N/TU for switching to different
> refresh rate dynamically. PIPECONF_EDP_RR_MODE_SWITCH bit helps toggle
> between alternate refresh rates programmed in 2nd M/N/TU registers.
>
> v2: Daniel's review comments
> Computing M2/N2 in compute_config and storing it in crtc_config
>
> v3: Modified reference to edp_downclock and edp_downclock_avail based on the
> changes made to move them from dev_private to intel_panel.
>
> v4: Modified references to is_drrs_supported based on the changes made to
> rename it to drrs_support.
>
> v5: Jani's review comments
> Removed superfluous return statements. Changed support for Gen 7 and above.
> Corrected indentation. Re-structured the code which finds crtc and connector
> from encoder. Changed some logs to be less verbose.
>
> v6: Modifying i915_drrs to include only intel connector as intel_dp can be
> derived from intel connector when required.
>
> v7: As per internal review comments, acquiring mutex just before accessing
> drrs RR. As per Chris's review comments, added documentation about the use
> of locking in the function.
>
> Signed-off-by: Pradeep Bhat <pradeep.bhat at intel.com>
> Signed-off-by: Vandana Kannan <vandana.kannan at intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 5 ++
> drivers/gpu/drm/i915/i915_reg.h | 1 +
> drivers/gpu/drm/i915/intel_dp.c | 108 ++++++++++++++++++++++++++++++++++++++
> drivers/gpu/drm/i915/intel_drv.h | 6 ++-
> 4 files changed, 119 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 6b4d0b20..43d3dfe 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -774,6 +774,10 @@ struct i915_fbc {
> } no_fbc_reason;
> };
>
> +struct i915_drrs {
> + struct intel_connector *connector;
> +};
> +
> struct i915_psr {
> bool sink_support;
> bool source_ok;
> @@ -1466,6 +1470,7 @@ typedef struct drm_i915_private {
> int num_plane;
>
> struct i915_fbc fbc;
> + struct i915_drrs drrs;
> struct intel_opregion opregion;
> struct intel_vbt_data vbt;
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index f73a49d..bfd7703 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -3225,6 +3225,7 @@
> #define PIPECONF_INTERLACED_DBL_ILK (4 << 21) /* ilk/snb only */
> #define PIPECONF_PFIT_PF_INTERLACED_DBL_ILK (5 << 21) /* ilk/snb only */
> #define PIPECONF_INTERLACE_MODE_MASK (7 << 21)
> +#define PIPECONF_EDP_RR_MODE_SWITCH (1 << 20)
> #define PIPECONF_CXSR_DOWNCLOCK (1<<16)
> #define PIPECONF_COLOR_RANGE_SELECT (1 << 13)
> #define PIPECONF_BPC_MASK (0x7 << 5)
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 39365bf..54cde57 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -832,6 +832,20 @@ intel_dp_set_clock(struct intel_encoder *encoder,
> }
> }
>
> +static void
> +intel_dp_set_m2_n2(struct intel_crtc *crtc, struct intel_link_m_n *m_n)
> +{
> + struct drm_device *dev = crtc->base.dev;
> + struct drm_i915_private *dev_priv = dev->dev_private;
> + enum transcoder transcoder = crtc->config.cpu_transcoder;
> +
> + I915_WRITE(PIPE_DATA_M2(transcoder),
> + TU_SIZE(m_n->tu) | m_n->gmch_m);
> + I915_WRITE(PIPE_DATA_N2(transcoder), m_n->gmch_n);
> + I915_WRITE(PIPE_LINK_M2(transcoder), m_n->link_m);
> + I915_WRITE(PIPE_LINK_N2(transcoder), m_n->link_n);
> +}
> +
> bool
> intel_dp_compute_config(struct intel_encoder *encoder,
> struct intel_crtc_config *pipe_config)
> @@ -936,6 +950,15 @@ found:
> pipe_config->port_clock,
> &pipe_config->dp_m_n);
>
> + if (intel_connector->panel.edp_downclock_avail &&
> + intel_dp->drrs_state.type == SEAMLESS_DRRS_SUPPORT) {
Again, seems like intel_connector->panel.edp_downclock_avail is useless
state. Why not just look at intel_connector->panel.downclock_mode !=
NULL?
> + intel_link_compute_m_n(bpp, lane_count,
> + intel_connector->panel.edp_downclock,
> + pipe_config->port_clock,
> + &pipe_config->dp_m2_n2);
> + }
> +
> +
> intel_dp_set_clock(encoder, pipe_config, intel_dp->link_bw);
>
> return true;
> @@ -3666,6 +3689,87 @@ intel_dp_init_panel_power_sequencer_registers(struct drm_device *dev,
> I915_READ(pp_div_reg));
> }
>
> +void intel_dp_set_drrs_state(struct drm_device *dev, int refresh_rate)
> +{
> + struct drm_i915_private *dev_priv = dev->dev_private;
> + struct intel_encoder *encoder;
> + struct intel_dp *intel_dp = NULL;
> + struct intel_crtc_config *config = NULL;
> + struct intel_crtc *intel_crtc = NULL;
> + struct intel_connector *intel_connector = dev_priv->drrs.connector;
This drrs.connector is also starting to look like extra state that could
be derived from somewhere else.
> + u32 reg, val;
> + int index = 0;
> +
> + if (refresh_rate <= 0) {
> + DRM_DEBUG_KMS("Refresh rate should be positive non-zero.\n");
> + return;
> + }
> +
> + if (intel_connector == NULL) {
> + DRM_DEBUG_KMS("DRRS supported for eDP only.\n");
> + return;
> + }
> +
> + encoder = intel_attached_encoder(&intel_connector->base);
> + intel_dp = enc_to_intel_dp(&encoder->base);
> + intel_crtc = encoder->new_crtc;
> +
> + if (!intel_crtc) {
> + DRM_DEBUG_KMS("DRRS: intel_crtc not initialized\n");
> + return;
> + }
> +
> + config = &intel_crtc->config;
> +
> + if (intel_dp->drrs_state.type < SEAMLESS_DRRS_SUPPORT) {
> + DRM_DEBUG_KMS("Seamless DRRS not supported.\n");
> + return;
> + }
> +
> + if (intel_connector->panel.fixed_mode->vrefresh == refresh_rate)
> + index = DRRS_HIGH_RR;
> + else
> + index = DRRS_LOW_RR;
> +
> + if (index == intel_dp->drrs_state.refresh_rate_type) {
> + DRM_DEBUG_KMS(
> + "DRRS requested for previously set RR...ignoring\n");
> + return;
> + }
> +
> + if (!intel_crtc->active) {
> + DRM_DEBUG_KMS("eDP encoder disabled. CRTC not Active\n");
> + return;
> + }
> +
> + if (INTEL_INFO(dev)->gen > 6 && INTEL_INFO(dev)->gen < 8) {
> + reg = PIPECONF(intel_crtc->config.cpu_transcoder);
> + val = I915_READ(reg);
> + if (index > DRRS_HIGH_RR) {
> + val |= PIPECONF_EDP_RR_MODE_SWITCH;
> + intel_dp_set_m2_n2(intel_crtc, &config->dp_m2_n2);
> + } else {
> + val &= ~PIPECONF_EDP_RR_MODE_SWITCH;
> + }
> + I915_WRITE(reg, val);
> + }
> +
> + /*
> + * mutex taken to ensure that there is no race between differnt
> + * drrs calls trying to update refresh rate. This scenario may occur
> + * in future when idleness detection based DRRS in kernel and
> + * possible calls from user space to set differnt RR are made.
> + */
> +
> + mutex_lock(&intel_dp->drrs_state.mutex);
Isn't this always done with dev->struct_mutex held? Why extra locking?
> +
> + intel_dp->drrs_state.refresh_rate_type = index;
> +
> + mutex_unlock(&intel_dp->drrs_state.mutex);
> +
> + DRM_DEBUG_KMS("eDP Refresh Rate set to : %dHz\n", refresh_rate);
> +}
> +
> static struct drm_display_mode *
> intel_dp_drrs_init(struct intel_digital_port *intel_dig_port,
> struct intel_connector *intel_connector,
> @@ -3701,6 +3805,10 @@ intel_dp_drrs_init(struct intel_digital_port *intel_dig_port,
> intel_connector->panel.edp_downclock =
> downclock_mode->clock;
>
> + dev_priv->drrs.connector = intel_connector;
> +
> + mutex_init(&intel_dp->drrs_state.mutex);
> +
> intel_dp->drrs_state.type = dev_priv->vbt.drrs_type;
>
> intel_dp->drrs_state.refresh_rate_type = DRRS_HIGH_RR;
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index c41c735..4f7c816 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -291,6 +291,9 @@ struct intel_crtc_config {
> int pipe_bpp;
> struct intel_link_m_n dp_m_n;
>
> + /* m2_n2 for eDP downclock */
> + struct intel_link_m_n dp_m2_n2;
> +
> /*
> * Frequence the dpll for the port should run at. Differs from the
> * adjusted dotclock e.g. for DP or 12bpc hdmi mode. This is also
> @@ -481,6 +484,7 @@ enum edp_drrs_refresh_rate_type {
> struct drrs_info {
> enum drrs_support_type type;
> enum edp_drrs_refresh_rate_type refresh_rate_type;
> + struct mutex mutex;
> };
>
> struct intel_dp {
> @@ -769,7 +773,7 @@ void intel_edp_panel_off(struct intel_dp *intel_dp);
> void intel_edp_psr_enable(struct intel_dp *intel_dp);
> void intel_edp_psr_disable(struct intel_dp *intel_dp);
> void intel_edp_psr_update(struct drm_device *dev);
> -
> +void intel_dp_set_drrs_state(struct drm_device *dev, int refresh_rate);
>
> /* intel_dsi.c */
> bool intel_dsi_init(struct drm_device *dev);
> --
> 1.7.9.5
>
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--
Jani Nikula, Intel Open Source Technology Center
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