[Intel-gfx] [PATCH 6/8] drm/i915/rpm: d3cold Policy
Rodrigo Vivi
rodrigo.vivi at intel.com
Wed Aug 3 20:45:37 UTC 2022
On Thu, Jul 21, 2022 at 03:29:53PM +0530, tilak.tangudu at intel.com wrote:
> From: Tilak Tangudu <tilak.tangudu at intel.com>
This needs to be sorted out... or the patch split or use
the Co-developed-by:...
>
> Add d3cold_sr_lmem_threshold modparam to choose between
> d3cold-off zero watt and d3hot/d3cold-VRAM Self Refresh.
> i915 requires to evict the lmem objects to smem in order to
> support d3cold-Off. if platform does not supports vram_sr
> feature then fall back to d3hot by disabling d3cold to
> avoid the rpm suspend/resume latency.
> Extend the d3cold_sr_lmem_threshold modparam to debugfs
> i915_params so that, it can be used by igt test.
>
> If gfx root port is not capable of sending PME from d3cold
> or doesn't have _PR3 power resources then only d3hot state
> can be supported.
>
> Adding intel_pm_prepare_targeted_d3_state() to choose the
> correct target d3 state and cache it to intel_runtime_pm
> structure, it can be used in rpm suspend/resume callback
> accordingly.
>
> v2: lmem->avail stopped tracking lmem usage since ttm is
> introduced, so removed lmem->avail usage in policy.
> FIXME here, lmem usage is not added, need to be added
> by using query functions.
> FIXME, Forcing the policy to enter D3COLD_OFF for
> validation purpose.
>
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
> Signed-off-by: Tilak Tangudu <tilak.tangudu at intel.com>
> ---
> drivers/gpu/drm/i915/i915_driver.c | 6 +++++
> drivers/gpu/drm/i915/i915_params.c | 5 ++++
> drivers/gpu/drm/i915/i915_params.h | 1 +
> drivers/gpu/drm/i915/intel_pm.c | 35 +++++++++++++++++++++++++
> drivers/gpu/drm/i915/intel_pm.h | 1 +
> drivers/gpu/drm/i915/intel_runtime_pm.h | 7 +++++
> 6 files changed, 55 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
> index 4c36554567fd..2b2e9563f149 100644
> --- a/drivers/gpu/drm/i915/i915_driver.c
> +++ b/drivers/gpu/drm/i915/i915_driver.c
> @@ -1581,6 +1581,12 @@ static int intel_runtime_idle(struct device *kdev)
> struct drm_i915_private *i915 = kdev_to_i915(kdev);
> int ret = 1;
>
> + disable_rpm_wakeref_asserts(&i915->runtime_pm);
> + ret = intel_pm_prepare_targeted_d3_state(i915);
> + if (!ret)
> + ret = 1;
why?
> +
> + enable_rpm_wakeref_asserts(&i915->runtime_pm);
> pm_runtime_mark_last_busy(kdev);
> pm_runtime_autosuspend(kdev);
>
> diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
> index 6fc475a5db61..4603f5c2ed77 100644
> --- a/drivers/gpu/drm/i915/i915_params.c
> +++ b/drivers/gpu/drm/i915/i915_params.c
> @@ -197,6 +197,11 @@ i915_param_named(enable_gvt, bool, 0400,
> "Enable support for Intel GVT-g graphics virtualization host support(default:false)");
> #endif
>
> +i915_param_named_unsafe(d3cold_sr_lmem_threshold, int, 0600,
> + "Enable VRAM Self refresh when size of lmem is greater to this threshold. "
> + "If VRAM Self Refresh is not available then fall back to d3cold. "
> + "It helps to optimize the suspend/resume latecy. (default: 300mb)");
> +
> #if CONFIG_DRM_I915_REQUEST_TIMEOUT
> i915_param_named_unsafe(request_timeout_ms, uint, 0600,
> "Default request/fence/batch buffer expiration timeout.");
> diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h
> index 2733cb6cfe09..1a86711038da 100644
> --- a/drivers/gpu/drm/i915/i915_params.h
> +++ b/drivers/gpu/drm/i915/i915_params.h
> @@ -75,6 +75,7 @@ struct drm_printer;
> param(unsigned int, request_timeout_ms, CONFIG_DRM_I915_REQUEST_TIMEOUT, CONFIG_DRM_I915_REQUEST_TIMEOUT ? 0600 : 0) \
> param(unsigned int, lmem_size, 0, 0400) \
> param(unsigned int, lmem_bar_size, 0, 0400) \
> + param(int, d3cold_sr_lmem_threshold, 300, 0600) \
> /* leave bools at the end to not create holes */ \
> param(bool, enable_hangcheck, true, 0600) \
> param(bool, load_detect_test, false, 0600) \
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index f06babdb3a8c..20b0638ecd5c 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -8287,6 +8287,41 @@ void intel_pm_setup(struct drm_i915_private *dev_priv)
> atomic_set(&dev_priv->runtime_pm.wakeref_count, 0);
> }
>
> +int intel_pm_prepare_targeted_d3_state(struct drm_i915_private *i915)
> +{
> + struct intel_runtime_pm *rpm = &i915->runtime_pm;
> + struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
> + u64 lmem_used = 0;
> + struct pci_dev *root_pdev;
> + int ret = 0;
> +
> + /* igfx will return from here */
then this patch is preventing runtime_pm on igfx no?!
or we need to return 0...
> + root_pdev = pcie_find_root_port(pdev);
> + if (!root_pdev)
> + return ret;
> +
> + /* D3Cold requires PME capability and _PR3 power resource */
> + if (!pci_pme_capable(root_pdev, PCI_D3cold) || !pci_pr3_present(root_pdev))
> + return ret;
If this is the case we probably need to block D3cold, but not D3hot, right?
> +
> + /* FXME query the LMEM usage and fill lmem_used */
> + /* Trigger D3COLD_OFF always to validate with all tests */
> + if (lmem_used < i915->params.d3cold_sr_lmem_threshold * 1024 * 1024) {
> + rpm->d3_state = INTEL_D3COLD_OFF;
> + drm_dbg(&i915->drm, "Prepared for D3Cold off\n");
> + } else {
> + /* Disable D3Cold to reduce the eviction latency */
> + rpm->d3_state = INTEL_D3HOT;
> + }
> +
> + if (rpm->d3_state == INTEL_D3HOT)
> + pci_d3cold_disable(root_pdev);
> + else
> + pci_d3cold_enable(root_pdev);
why not merge these both if states?
> +
> + return ret;
> +}
> +
> static struct intel_global_state *intel_dbuf_duplicate_state(struct intel_global_obj *obj)
> {
> struct intel_dbuf_state *dbuf_state;
> diff --git a/drivers/gpu/drm/i915/intel_pm.h b/drivers/gpu/drm/i915/intel_pm.h
> index 945503ae493e..7827b0c1a2f3 100644
> --- a/drivers/gpu/drm/i915/intel_pm.h
> +++ b/drivers/gpu/drm/i915/intel_pm.h
> @@ -31,6 +31,7 @@ int ilk_wm_max_level(const struct drm_i915_private *dev_priv);
> void intel_init_pm(struct drm_i915_private *dev_priv);
> void intel_init_clock_gating_hooks(struct drm_i915_private *dev_priv);
> void intel_pm_setup(struct drm_i915_private *dev_priv);
> +int intel_pm_prepare_targeted_d3_state(struct drm_i915_private *i915);
> void g4x_wm_get_hw_state(struct drm_i915_private *dev_priv);
> void vlv_wm_get_hw_state(struct drm_i915_private *dev_priv);
> void ilk_wm_get_hw_state(struct drm_i915_private *dev_priv);
> diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.h b/drivers/gpu/drm/i915/intel_runtime_pm.h
> index 99418c3a934a..568559b71b70 100644
> --- a/drivers/gpu/drm/i915/intel_runtime_pm.h
> +++ b/drivers/gpu/drm/i915/intel_runtime_pm.h
> @@ -22,6 +22,12 @@ enum i915_drm_suspend_mode {
> I915_DRM_SUSPEND_HIBERNATE,
> };
>
> +enum intel_gfx_d3_state {
> + INTEL_D3HOT,
> + INTEL_D3COLD_OFF,
> + INTEL_D3COLD_VRAM_SR,
> +};
> +
> /*
> * This struct helps tracking the state needed for runtime PM, which puts the
> * device in PCI D3 state. Notice that when this happens, nothing on the
> @@ -52,6 +58,7 @@ struct intel_runtime_pm {
> bool suspended;
> bool irqs_enabled;
> bool no_wakeref_tracking;
> + enum intel_gfx_d3_state d3_state;
>
> #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
> /*
> --
> 2.25.1
>
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