[Intel-gfx] [PATCH 3/5] drm/i915: Add support for DRRS to switch RR
Vandana Kannan
vandana.kannan at intel.com
Thu Jan 30 04:37:42 CET 2014
On Jan-22-2014 7:44 PM, Jani Nikula wrote:
> On Mon, 23 Dec 2013, 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.
>>
>> 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_reg.h | 1 +
>> drivers/gpu/drm/i915/intel_dp.c | 106 ++++++++++++++++++++++++++++++++++++++
>> drivers/gpu/drm/i915/intel_drv.h | 6 ++-
>> 3 files changed, 112 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>> index f1eece4..57d2b64 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -3206,6 +3206,7 @@
>> #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 079b53f..d1e1d6e 100644
>> --- a/drivers/gpu/drm/i915/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/intel_dp.c
>> @@ -791,6 +791,21 @@ 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);
>> + return;
>
> Superfluous return statement.
>
Ok.
>> +}
>> +
>> bool
>> intel_dp_compute_config(struct intel_encoder *encoder,
>> struct intel_crtc_config *pipe_config)
>> @@ -894,6 +909,14 @@ found:
>> pipe_config->port_clock,
>> &pipe_config->dp_m_n);
>>
>> + if (intel_connector->panel.edp_downclock_avail &&
>> + intel_dp->drrs_state.drrs_support == SEAMLESS_DRRS_SUPPORT) {
>> + intel_link_compute_m_n(bpp, lane_count,
>> + intel_connector->panel.edp_downclock,
>> + pipe_config->port_clock,
>> + &pipe_config->dp_m2_n2);
>> + }
>
> Indentation in the above block.
>
Ok.
>> +
>> intel_dp_set_clock(encoder, pipe_config, intel_dp->link_bw);
>>
>> return true;
>> @@ -3522,6 +3545,87 @@ 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) {
>
> The opening brace belongs on a new line.
>
Ok.
>> + struct drm_i915_private *dev_priv = dev->dev_private;
>> + struct drm_mode_config *mode_config = &dev->mode_config;
>> + 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 = NULL;
>> + bool found_edp = false;
>> + u32 reg, val;
>> + int index = 0;
>> +
>> + if (refresh_rate <= 0) {
>> + DRM_INFO("Refresh rate should be positive non-zero.\n");
>> + goto out;
>> + }
>
> Under what conditions do you expect this to happen?
>
In future, when refresh rate switching based on user space requests will
be implemented, intel_dp_set_drrs_state() will be used. This check here
is to safeguard calls from user space.
>> +
>> + list_for_each_entry(encoder, &mode_config->encoder_list, base.head) {
>> + if (encoder->type == INTEL_OUTPUT_EDP) {
>> + intel_dp = enc_to_intel_dp(&encoder->base);
>> + intel_crtc = encoder->new_crtc;
>> + if (!intel_crtc) {
>> + DRM_INFO("DRRS: intel_crtc not initialized\n");
>
> DRM_INFO is probably a bit verbose.
>
>> + goto out;
>> + }
>> + config = &intel_crtc->config;
>> + intel_connector = intel_dp->attached_connector;
>> + found_edp = true;
>> + break;
>> + }
>> + }
>
> I'm confused. You go through all the trouble of saving the crtc and the
> connector (although only in the next patch) but here you iterate all the
> encoders to find the one. Why?
>
>> +
>> + if (!found_edp) {
>
> There's no need to add an extra variable for this. You already have
> intel_dp, intel_crtc, config and intel_connector you can check!
>
Ok. I will make necessary changes.
>> + DRM_INFO("DRRS supported for eDP only.\n");
>> + goto out;
>> + }
>> +
>> + if (intel_dp->drrs_state.drrs_support < SEAMLESS_DRRS_SUPPORT) {
>> + DRM_INFO("Seamless DRRS not supported.\n");
>> + goto out;
>> + }
>> +
>> + if (intel_connector->panel.fixed_mode->vrefresh == refresh_rate)
>> + index = DRRS_HIGH_RR;
>> + else
>> + index = DRRS_LOW_RR;
>> +
>> + if (index == intel_dp->drrs_state.drrs_refresh_rate_type) {
>> + DRM_INFO("DRRS requested for previously set RR...ignoring\n");
>> + goto out;
>> + }
>> +
>> + if (!intel_crtc->active) {
>> + DRM_INFO("eDP encoder has been disabled. CRTC not Active\n");
>> + goto out;
>> + }
>> +
>> + mutex_lock(&intel_dp->drrs_state.mutex);
>> +
>> + /* Haswell and below */
>> + if (INTEL_INFO(dev)->gen >= 5 && 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;
>
> Please check bspec for workarounds you need to do wrt frame start delay
> before enabling the pipe/transcoder.
>
We checked the BSpec and there was no workaround mentioned for this part.
>> + intel_dp_set_m2_n2(intel_crtc, &config->dp_m2_n2);
>> + } else
>> + val &= ~PIPECONF_EDP_RR_MODE_SWITCH;
>
> Per coding style, if one branch needs braces, then all do.
>
Ok.
>> + I915_WRITE(reg, val);
>> + }
>> +
>> + intel_dp->drrs_state.drrs_refresh_rate_type = index;
>> + DRM_INFO("eDP Refresh Rate set to : %dHz\n", refresh_rate);
>> +
>> + mutex_unlock(&intel_dp->drrs_state.mutex);
>> +
>> +out:
>> + return;
>
> Superfluous return statement.
>
Ok.
>> +}
>> +
>> static void
>> intel_dp_drrs_initialize(struct intel_digital_port *intel_dig_port,
>> struct intel_connector *intel_connector,
>> @@ -3555,6 +3659,8 @@ intel_dp_drrs_initialize(struct intel_digital_port *intel_dig_port,
>> intel_connector->panel.edp_downclock =
>> intel_connector->panel.downclock_mode->clock;
>>
>> + mutex_init(&intel_dp->drrs_state.mutex);
>> +
>> intel_dp->drrs_state.drrs_support = dev_priv->vbt.drrs_mode;
>>
>> intel_dp->drrs_state.drrs_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 d208bf5..d1c60fa 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
>> @@ -489,6 +492,7 @@ enum edp_drrs_refresh_rate_type {
>> struct drrs_info {
>> enum drrs_support_type drrs_support;
>> enum edp_drrs_refresh_rate_type drrs_refresh_rate_type;
>> + struct mutex mutex;
>> };
>>
>> struct intel_dp {
>> @@ -761,7 +765,7 @@ void ironlake_edp_panel_vdd_off(struct intel_dp *intel_dp, bool sync);
>> 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);
>> -
>> +extern void intel_dp_set_drrs_state(struct drm_device *dev, int refresh_rate);
>
> No need for the "extern".
>
Ok.
>>
>> /* intel_dsi.c */
>> bool intel_dsi_init(struct drm_device *dev);
>> --
>> 1.7.9.5
>>
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>
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