[Intel-gfx] [PATCH 3/5] drm/i915: Add support for DRRS to switch RR
Vandana Kannan
vandana.kannan at intel.com
Mon Feb 3 04:46:28 CET 2014
On Jan-30-2014 12:22 PM, Jani Nikula wrote:
> On Thu, 30 Jan 2014, Vandana Kannan <vandana.kannan at intel.com> wrote:
>> 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.
>
> Oh, I'm sorry, I should have been more specific. This was in the SNB
> specs: "Workaround : If this pipe is connected to a port on the PCH and
> this power savings mode will be used, then before the pipe and
> transcoder are enabled, the frame start delay in the pipe and transcoder
> must be set to 11b. When these conditions are no longer true, the frame
> start delay must be returned to the previous value after the pipe and
> transcoder are disabled."
>
> Going forward, I think it's okay to enable drrs on ivb+ at first, and
> enable snb with the workarounds in a follow-up patch. Others may
> disagree...
>
SNB support will be added as a separate patch. I will modify the checks
wherever applicable to include Gen6+
>>>> + 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
>>>>
>>>> _______________________________________________
>>>> Intel-gfx mailing list
>>>> Intel-gfx at lists.freedesktop.org
>>>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>>>
>>
>
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