[Intel-gfx] [PATCH] drm/i915: Idleness detection for DRRS
Daniel Vetter
daniel at ffwll.ch
Mon Aug 25 23:12:07 CEST 2014
On Fri, Aug 15, 2014 at 10:57:08PM +0530, Vandana Kannan wrote:
> On Aug-07-2014 7:27 PM, Daniel Vetter wrote:
> > Hi Vandana,
> >
> > I think we need to start over from a fresh&clean slate with this part
> > - too much changed and all the differen revisions of this patch don't
> > provide that much information.
> >
> > Also as Chris says this introduces yet another idleness detection
> > system, and we already have plenty of them.
> >
> > High-level comments:
> >
> > - We now have the frontbuffer tracking infrastructure, see the various
> > new intel_frontbuffer_* and similar functions in intel_display.c. They
> > have nice kerneldoc explaining what exactly they do. We need to hook
> > into that instead of creating new idlesness detection.
> >
> Hi Daniel,
>
> Could you point me to this documentation? I cant find it - might be
> missing something..
Essentially the kerneldoc comments added in f99d70690e075
Unfortunately (mostly because intel_display.c is one giant mess) this is
not yet extracted into the overal HTML rendering of all drm/i915
documentation at:
http://people.freedesktop.org/~danvet/drm/
Currently only PSR uses this, but Rodrigo is working on patches to make
FBC also use this to detect frontbuffer updates. Might be useful to chat
with Rodrigo about this, too.
For DRRS it is probably best to hook intel_mark_fb_busy and then rearm a
idle timer (or work item, depending upon the chosen locking scheme) just
for DRRS to go back to the slow clock. The legacy DRRS functions
(increase/decrease_pllclock) are also wired up similarly, but you can't
use them as an exact template: They don't do locking, and the mark_idle is
really pessimistic - with a simple per-crtc DRRS timer we can be a lot
more precise.
> Apart from this idleness detection patch, there are 2 other patches
> which just set the appropriate registers for bdw and vlv (in
> set_drrs()). These 2 patches have got R-b from Jani and need rebasing. I
> was wondering if I could resend those patches - they won't have an
> effect until DRRS trigger is in place..
tbh I've lost track of all the DRRS stuff a bit. Might be useful to rebase
all the remaining patches so that we have an overview again.
But better to do that only after we've sketched the DRRS integration under
discussion here.
Thanks, Daniel
>
> - Vandana
> > - There's already calls to intel_increase/decrease_pllclock. That
> > should be renamed to gmch_increase/decrease_pllclock, and we the new
> > dp drrs support here should be called at _exactly_ the same spots.
> >
> > - This doesn't use the pipe config we've added at all - DRRS shouldn't
> > look at the panel, but only at the pipe config to figure out whether
> > drrs is supported on a given pipe or not. There is also no need to
> > restrict DRRS to single pipe mode at all.
> >
> > - Locking is important. In case of doubt follow the example
> > established by the new PSR code. Especially important is to not
> > require modeset locks.
> >
> > - There's no need to disable DRRS from the PSR (or fbc) code at all,
> > the frontbuffer tracking code will take care of all this. And just
> > using pageflips as business signal isn't good enough.
> >
> > This is just a rough guideline, I think it'd be good to first hash out
> > the rough design in more detail (maybe as a patch with just
> > pseudo-code) before starting with codeing.
> >
> > Thanks, Daniel
> >
> >
> >
> > On Thu, Aug 7, 2014 at 3:45 PM, Vandana Kannan <vandana.kannan at intel.com> wrote:
> >> Adding support to detect display idleness by tracking page flip from
> >> user space. Switch to low refresh rate is triggered after 2 seconds of
> >> idleness. The delay is configurable. If there is a page flip or call to
> >> update the plane, then high refresh rate is applied.
> >> The feature is not used in dual-display mode.
> >>
> >> v2: Chris Wilson's review comments incorporated.
> >> Modify idleness detection implementation to make it similar to the
> >> implementation of intel_update_fbc/intel_disable_fbc
> >>
> >> v3: Internal review comments incorporated
> >> Add NULL pointer check in intel_disable_drrs.
> >> Add drrs calls in i9xx_crtc_enable/disable and valleyview_crtc_enable.
> >>
> >> v4: Jani's review comments incorporated.
> >> Change in sequence in intel_update_drrs. Comment modified to remove details
> >> of update param. Modified DRRS idleness interval to a module parameter.
> >>
> >> v5: Chris's review comments incorporated.
> >> Initialize connector in idleness detection init. Modifications made to
> >> use only intel_connector in i915_drrs and derive intel_dp when required.
> >> Added a function drrs_fini to cleanup DRRS work.
> >>
> >> v6: Internal review comments. Removed check for primary enabled, which is
> >> a redundant check, in the case of clone mode. Added a flag to track
> >> dual-display configuration. Remove print statement for "cancel DRR work"
> >> and print "DRRS not supported" only once.
> >>
> >> v7: As per internal review comments, removing calls to update/disable drrs
> >> from sprite update path. For sprite, all drrs related updates would be
> >> taken care of with calls to crtc page flip itself. This will have to be
> >> revisited later if flip infrastructure changes for sprite.
> >>
> >> v8: Incorporated Jani's review comments. Added space after the periods in the
> >> module param description. Changes around drrs-fini to remove seamless DRRS
> >> check.
> >>
> >> v9: Added checks for PSR before updating DRRS. Added check for module
> >> param drrs_interval before updating DRRS (this is required if the interval
> >> is modified by the user during system use). DRRS disabled by default. Changes
> >> based on Jani's review comments
> >>
> >> v10: Disable/enable DRRS when PSR is enable/disabled.
> >>
> >> v11: Moved DRRS not supported log to patch2.
> >>
> >> Patch rebased.
> >>
> >> Signed-off-by: Vandana Kannan <vandana.kannan at intel.com>
> >> Signed-off-by: Pradeep Bhat <pradeep.bhat at intel.com>
> >> Reviewed-by: Jani Nikula <jani.nikula at intel.com>
> >> Cc: Daniel Vetter <daniel at ffwll.ch>
> >> ---
> >> drivers/gpu/drm/i915/i915_drv.h | 7 ++
> >> drivers/gpu/drm/i915/i915_params.c | 8 ++
> >> drivers/gpu/drm/i915/intel_display.c | 13 ++++
> >> drivers/gpu/drm/i915/intel_dp.c | 27 ++++++-
> >> drivers/gpu/drm/i915/intel_drv.h | 5 +-
> >> drivers/gpu/drm/i915/intel_pm.c | 142 +++++++++++++++++++++++++++++++++++
> >> 6 files changed, 200 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> >> index 125a83c..993fdb1 100644
> >> --- a/drivers/gpu/drm/i915/i915_drv.h
> >> +++ b/drivers/gpu/drm/i915/i915_drv.h
> >> @@ -667,6 +667,12 @@ struct i915_fbc {
> >>
> >> struct i915_drrs {
> >> struct intel_connector *connector;
> >> + bool is_clone;
> >> + struct intel_drrs_work {
> >> + struct delayed_work work;
> >> + struct drm_crtc *crtc;
> >> + int interval;
> >> + } *drrs_work;
> >> };
> >>
> >> struct intel_dp;
> >> @@ -2156,6 +2162,7 @@ struct i915_params {
> >> int enable_ips;
> >> int invert_brightness;
> >> int enable_cmd_parser;
> >> + int drrs_interval;
> >> /* leave bools at the end to not create holes */
> >> bool enable_hangcheck;
> >> bool fastboot;
> >> diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
> >> index 62ee830..912a02f 100644
> >> --- a/drivers/gpu/drm/i915/i915_params.c
> >> +++ b/drivers/gpu/drm/i915/i915_params.c
> >> @@ -50,6 +50,7 @@ struct i915_params i915 __read_mostly = {
> >> .disable_vtd_wa = 0,
> >> .use_mmio_flip = 0,
> >> .mmio_debug = 0,
> >> + .drrs_interval = 0,
> >> };
> >>
> >> module_param_named(modeset, i915.modeset, int, 0400);
> >> @@ -167,3 +168,10 @@ module_param_named(mmio_debug, i915.mmio_debug, bool, 0600);
> >> MODULE_PARM_DESC(mmio_debug,
> >> "Enable the MMIO debug code (default: false). This may negatively "
> >> "affect performance.");
> >> +
> >> +module_param_named(drrs_interval, i915.drrs_interval, int, 0600);
> >> +MODULE_PARM_DESC(drrs_interval,
> >> + "DRRS idleness detection interval (default: 0 ms). "
> >> + "If this field is set to 0, then seamless DRRS feature "
> >> + "based on idleness detection is disabled. "
> >> + "The interval is to be set in milliseconds.");
> >> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> >> index 89e0ac5..da24f4e 100644
> >> --- a/drivers/gpu/drm/i915/intel_display.c
> >> +++ b/drivers/gpu/drm/i915/intel_display.c
> >> @@ -2743,6 +2743,7 @@ intel_pipe_set_base(struct drm_crtc *crtc, int x, int y,
> >>
> >> mutex_lock(&dev->struct_mutex);
> >> intel_update_fbc(dev);
> >> + intel_update_drrs(dev);
> >> mutex_unlock(&dev->struct_mutex);
> >>
> >> return 0;
> >> @@ -3897,6 +3898,7 @@ static void intel_crtc_enable_planes(struct drm_crtc *crtc)
> >>
> >> mutex_lock(&dev->struct_mutex);
> >> intel_update_fbc(dev);
> >> + intel_update_drrs(dev);
> >> mutex_unlock(&dev->struct_mutex);
> >>
> >> /*
> >> @@ -4213,6 +4215,7 @@ static void ironlake_crtc_disable(struct drm_crtc *crtc)
> >>
> >> mutex_lock(&dev->struct_mutex);
> >> intel_update_fbc(dev);
> >> + intel_update_drrs(dev);
> >> mutex_unlock(&dev->struct_mutex);
> >> }
> >>
> >> @@ -4260,6 +4263,7 @@ static void haswell_crtc_disable(struct drm_crtc *crtc)
> >>
> >> mutex_lock(&dev->struct_mutex);
> >> intel_update_fbc(dev);
> >> + intel_update_drrs(dev);
> >> mutex_unlock(&dev->struct_mutex);
> >>
> >> if (intel_crtc_to_shared_dpll(intel_crtc))
> >> @@ -4894,6 +4898,7 @@ static void i9xx_crtc_disable(struct drm_crtc *crtc)
> >>
> >> mutex_lock(&dev->struct_mutex);
> >> intel_update_fbc(dev);
> >> + intel_update_drrs(dev);
> >> mutex_unlock(&dev->struct_mutex);
> >> }
> >>
> >> @@ -9200,6 +9205,10 @@ static void intel_unpin_work_fn(struct work_struct *__work)
> >> drm_gem_object_unreference(&work->old_fb_obj->base);
> >>
> >> intel_update_fbc(dev);
> >> + /* disable current DRRS work scheduled and restart
> >> + * to push work by another x seconds
> >> + */
> >> + intel_update_drrs(dev);
> >> mutex_unlock(&dev->struct_mutex);
> >>
> >> intel_frontbuffer_flip_complete(dev, INTEL_FRONTBUFFER_PRIMARY(pipe));
> >> @@ -9851,6 +9860,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
> >> INTEL_FRONTBUFFER_PRIMARY(pipe));
> >>
> >> intel_disable_fbc(dev);
> >> + intel_disable_drrs(dev);
> >> intel_frontbuffer_flip_prepare(dev, INTEL_FRONTBUFFER_PRIMARY(pipe));
> >> mutex_unlock(&dev->struct_mutex);
> >>
> >> @@ -12728,6 +12738,7 @@ void intel_modeset_init(struct drm_device *dev)
> >>
> >> /* Just in case the BIOS is doing something questionable. */
> >> intel_disable_fbc(dev);
> >> + intel_disable_drrs(dev);
> >>
> >> drm_modeset_lock_all(dev);
> >> intel_modeset_setup_hw_state(dev, false);
> >> @@ -13226,6 +13237,8 @@ void intel_modeset_cleanup(struct drm_device *dev)
> >>
> >> intel_disable_fbc(dev);
> >>
> >> + intel_disable_drrs(dev);
> >> +
> >> intel_disable_gt_powersave(dev);
> >>
> >> ironlake_teardown_rc6(dev);
> >> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> >> index 34e3c47..6b8de96 100644
> >> --- a/drivers/gpu/drm/i915/intel_dp.c
> >> +++ b/drivers/gpu/drm/i915/intel_dp.c
> >> @@ -1872,6 +1872,11 @@ void intel_edp_psr_enable(struct intel_dp *intel_dp)
> >>
> >> dev_priv->psr.busy_frontbuffer_bits = 0;
> >>
> >> + if (INTEL_INFO(dev)->gen < 8) {
> >> + DRM_DEBUG_KMS("Enabling PSR, disabling DRRS\n");
> >> + intel_disable_drrs(dev);
> >> + }
> >> +
> >> /* Setup PSR once */
> >> intel_edp_psr_setup(intel_dp);
> >>
> >> @@ -1909,6 +1914,9 @@ void intel_edp_psr_disable(struct intel_dp *intel_dp)
> >> mutex_unlock(&dev_priv->psr.lock);
> >>
> >> cancel_delayed_work_sync(&dev_priv->psr.work);
> >> +
> >> + if (INTEL_INFO(dev)->gen < 8)
> >> + intel_update_drrs(dev);
> >> }
> >>
> >> static void intel_edp_psr_work(struct work_struct *work)
> >> @@ -3981,17 +3989,34 @@ intel_dp_connector_destroy(struct drm_connector *connector)
> >> kfree(connector);
> >> }
> >>
> >> +static void
> >> +intel_dp_drrs_fini(struct drm_i915_private *dev_priv)
> >> +{
> >> + if (cancel_delayed_work_sync(&dev_priv->drrs.drrs_work->work)) {
> >> + kfree(dev_priv->drrs.drrs_work);
> >> + dev_priv->drrs.drrs_work = NULL;
> >> + dev_priv->drrs.connector = NULL;
> >> + }
> >> +}
> >> +
> >> void intel_dp_encoder_destroy(struct drm_encoder *encoder)
> >> {
> >> struct intel_digital_port *intel_dig_port = enc_to_dig_port(encoder);
> >> struct intel_dp *intel_dp = &intel_dig_port->dp;
> >> struct drm_device *dev = intel_dp_to_dev(intel_dp);
> >> + struct drm_i915_private *dev_priv = dev->dev_private;
> >>
> >> drm_dp_aux_unregister(&intel_dp->aux);
> >> intel_dp_mst_encoder_cleanup(intel_dig_port);
> >> drm_encoder_cleanup(encoder);
> >> if (is_edp(intel_dp)) {
> >> cancel_delayed_work_sync(&intel_dp->panel_vdd_work);
> >> +
> >> + if (dev_priv->drrs.connector && dev_priv->drrs.drrs_work &&
> >> + intel_dp == enc_to_intel_dp(
> >> + &dev_priv->drrs.connector->encoder->base))
> >> + intel_dp_drrs_fini(dev_priv);
> >> +
> >> drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
> >> edp_panel_vdd_off_sync(intel_dp);
> >> drm_modeset_unlock(&dev->mode_config.connection_mutex);
> >> @@ -4445,7 +4470,7 @@ intel_dp_drrs_init(struct intel_digital_port *intel_dig_port,
> >> return NULL;
> >> }
> >>
> >> - dev_priv->drrs.connector = intel_connector;
> >> + intel_init_drrs_idleness_detection(dev, intel_connector);
> >>
> >> mutex_init(&intel_dp->drrs_state.mutex);
> >>
> >> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> >> index 666ca8a..f34a6d0 100644
> >> --- a/drivers/gpu/drm/i915/intel_drv.h
> >> +++ b/drivers/gpu/drm/i915/intel_drv.h
> >> @@ -1077,7 +1077,10 @@ void intel_runtime_pm_put(struct drm_i915_private *dev_priv);
> >> void intel_init_runtime_pm(struct drm_i915_private *dev_priv);
> >> void intel_fini_runtime_pm(struct drm_i915_private *dev_priv);
> >> void ilk_wm_get_hw_state(struct drm_device *dev);
> >> -
> >> +void intel_init_drrs_idleness_detection(struct drm_device *dev,
> >> + struct intel_connector *connector);
> >> +void intel_update_drrs(struct drm_device *dev);
> >> +void intel_disable_drrs(struct drm_device *dev);
> >>
> >> /* intel_sdvo.c */
> >> bool intel_sdvo_init(struct drm_device *dev, uint32_t sdvo_reg, bool is_sdvob);
> >> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> >> index 41de760..6fbbde5 100644
> >> --- a/drivers/gpu/drm/i915/intel_pm.c
> >> +++ b/drivers/gpu/drm/i915/intel_pm.c
> >> @@ -644,6 +644,148 @@ out_disable:
> >> i915_gem_stolen_cleanup_compression(dev);
> >> }
> >>
> >> +static void intel_drrs_work_fn(struct work_struct *__work)
> >> +{
> >> + struct intel_drrs_work *work =
> >> + container_of(to_delayed_work(__work),
> >> + struct intel_drrs_work, work);
> >> + struct drm_device *dev = work->crtc->dev;
> >> + struct drm_i915_private *dev_priv = dev->dev_private;
> >> +
> >> + /* Double check if the dual-display mode is active. */
> >> + if (dev_priv->drrs.is_clone)
> >> + return;
> >> +
> >> + intel_dp_set_drrs_state(work->crtc->dev,
> >> + dev_priv->drrs.connector->panel.downclock_mode->vrefresh);
> >> +}
> >> +
> >> +static void intel_cancel_drrs_work(struct drm_i915_private *dev_priv)
> >> +{
> >> + if (dev_priv->drrs.drrs_work == NULL)
> >> + return;
> >> +
> >> + cancel_delayed_work_sync(&dev_priv->drrs.drrs_work->work);
> >> +}
> >> +
> >> +static void intel_enable_drrs(struct drm_crtc *crtc)
> >> +{
> >> + struct drm_device *dev = crtc->dev;
> >> + struct drm_i915_private *dev_priv = dev->dev_private;
> >> + struct intel_dp *intel_dp = NULL;
> >> +
> >> + intel_dp = enc_to_intel_dp(&dev_priv->drrs.connector->encoder->base);
> >> +
> >> + if (intel_dp == NULL)
> >> + return;
> >> +
> >> + intel_cancel_drrs_work(dev_priv);
> >> +
> >> + if (intel_dp->drrs_state.refresh_rate_type != DRRS_LOW_RR) {
> >> + dev_priv->drrs.drrs_work->crtc = crtc;
> >> + dev_priv->drrs.drrs_work->interval = i915.drrs_interval;
> >> +
> >> + /* Delay the actual enabling to let pageflipping cease and the
> >> + * display to settle before starting DRRS
> >> + */
> >> + schedule_delayed_work(&dev_priv->drrs.drrs_work->work,
> >> + msecs_to_jiffies(dev_priv->drrs.drrs_work->interval));
> >> + }
> >> +}
> >> +
> >> +void intel_disable_drrs(struct drm_device *dev)
> >> +{
> >> + struct drm_i915_private *dev_priv = dev->dev_private;
> >> + struct intel_dp *intel_dp = NULL;
> >> +
> >> + if (dev_priv->drrs.connector == NULL)
> >> + return;
> >> +
> >> + intel_dp = enc_to_intel_dp(&dev_priv->drrs.connector->encoder->base);
> >> +
> >> + if (intel_dp == NULL)
> >> + return;
> >> +
> >> + /* as part of disable DRRS, reset refresh rate to HIGH_RR */
> >> + if (intel_dp->drrs_state.refresh_rate_type == DRRS_LOW_RR) {
> >> + intel_cancel_drrs_work(dev_priv);
> >> + intel_dp_set_drrs_state(dev,
> >> + dev_priv->drrs.connector->panel.fixed_mode->vrefresh);
> >> + }
> >> +}
> >> +
> >> +/**
> >> + * intel_update_drrs - enable/disable DRRS as needed
> >> + * @dev: the drm_device
> >> +*/
> >> +void intel_update_drrs(struct drm_device *dev)
> >> +{
> >> + struct drm_crtc *crtc = NULL, *tmp_crtc;
> >> + struct drm_i915_private *dev_priv = dev->dev_private;
> >> +
> >> + if (i915.drrs_interval == 0) {
> >> + intel_disable_drrs(dev);
> >> + return;
> >> + }
> >> +
> >> + /* if drrs.connector is NULL, then drrs_init did not get called.
> >> + * which means DRRS is not supported.
> >> + */
> >> + if (dev_priv->drrs.connector == NULL)
> >> + return;
> >> +
> >> + if (dev_priv->drrs.connector->panel.downclock_mode == NULL)
> >> + return;
> >> +
> >> + list_for_each_entry(tmp_crtc, &dev->mode_config.crtc_list, head) {
> >> + if (intel_crtc_active(tmp_crtc)) {
> >> + if (crtc) {
> >> + DRM_DEBUG_KMS(
> >> + "more than one pipe active, disabling DRRS\n");
> >> + dev_priv->drrs.is_clone = true;
> >> + intel_disable_drrs(dev);
> >> + return;
> >> + }
> >> + crtc = tmp_crtc;
> >> + }
> >> + }
> >> +
> >> + if (crtc == NULL) {
> >> + DRM_DEBUG_KMS("DRRS: crtc not initialized\n");
> >> + return;
> >> + }
> >> +
> >> + dev_priv->drrs.is_clone = false;
> >> + intel_disable_drrs(dev);
> >> +
> >> + /* re-enable idleness detection */
> >> + intel_enable_drrs(crtc);
> >> +}
> >> +
> >> +void intel_init_drrs_idleness_detection(struct drm_device *dev,
> >> + struct intel_connector *connector)
> >> +{
> >> + struct intel_drrs_work *work;
> >> + struct drm_i915_private *dev_priv = dev->dev_private;
> >> +
> >> + if (i915.drrs_interval == 0)
> >> + DRM_INFO("DRRS disable by flag\n");
> >> +
> >> + work = kzalloc(sizeof(struct intel_drrs_work), GFP_KERNEL);
> >> + if (!work) {
> >> + DRM_ERROR("Failed to allocate DRRS work structure\n");
> >> + return;
> >> + }
> >> +
> >> + dev_priv->drrs.connector = connector;
> >> + dev_priv->drrs.is_clone = false;
> >> +
> >> + work->interval = i915.drrs_interval;
> >> + INIT_DELAYED_WORK(&work->work, intel_drrs_work_fn);
> >> +
> >> + dev_priv->drrs.drrs_work = work;
> >> +}
> >> +
> >> static void i915_pineview_get_mem_freq(struct drm_device *dev)
> >> {
> >> struct drm_i915_private *dev_priv = dev->dev_private;
> >> --
> >> 2.0.1
> >>
> >
> >
> >
>
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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