[Intel-gfx] [PATCH 14/15] drm/i915: vlv: add runtime PM support
Paulo Zanoni
przanoni at gmail.com
Wed Apr 9 18:40:03 CEST 2014
2014-04-08 13:57 GMT-03:00 Imre Deak <imre.deak at intel.com>:
> Add runtime PM support for VLV, but leave it disabled. The next patch
> enables it.
>
> The suspend/resume sequence used is based on [1] and [2]. In practice we
> depend on the GT RC6 mechanism to save the HW context depending on the
> render and media power wells. By the time we run the runtime suspend
> callback the display side is also off and the HW context for that is
> managed by the display power domain framework.
>
> Besides the above there are Gunit registers that depend on a system-wide
> power well. This power well goes off once the device enters any of the
> S0i[R123] states. To handle this scenario, save/restore these Gunit
> registers. Note that this is not the complete register set dictated by
> [2], to remove some overhead registers that are known not to be used are
> ignored. Also some registers are fully setup by initialization functions
> called during resume, these are not saved either. The list of registers
> can be further reduced, see the TODO note in the code.
>
> [1] VLV_gfx_clocking_PM_reset_y12w21d3 / "Driver D3 entry/exit"
> [2] VLV2_S0IXRegs
>
> Signed-off-by: Imre Deak <imre.deak at intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.c | 170 +++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 166 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 9f9d0db..16ca37f 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -891,19 +891,23 @@ static int i915_pm_poweroff(struct device *dev)
> return i915_drm_freeze(drm_dev);
> }
>
> -static void snb_runtime_suspend(struct drm_i915_private *dev_priv)
> +static int snb_runtime_suspend(struct drm_i915_private *dev_priv)
> {
> struct drm_device *dev = dev_priv->dev;
>
> intel_runtime_pm_disable_interrupts(dev);
> +
> + return 0;
> }
>
> -static void hsw_runtime_suspend(struct drm_i915_private *dev_priv)
> +static int hsw_runtime_suspend(struct drm_i915_private *dev_priv)
> {
> hsw_enable_pc8(dev_priv);
> +
> + return 0;
> }
>
> -static void snb_runtime_resume(struct drm_i915_private *dev_priv)
> +static int snb_runtime_resume(struct drm_i915_private *dev_priv)
> {
> struct drm_device *dev = dev_priv->dev;
>
> @@ -913,11 +917,15 @@ static void snb_runtime_resume(struct drm_i915_private *dev_priv)
> mutex_lock(&dev_priv->rps.hw_lock);
> gen6_update_ring_freq(dev);
> mutex_unlock(&dev_priv->rps.hw_lock);
> +
> + return 0;
> }
>
> -static void hsw_runtime_resume(struct drm_i915_private *dev_priv)
> +static int hsw_runtime_resume(struct drm_i915_private *dev_priv)
> {
> hsw_disable_pc8(dev_priv);
> +
> + return 0;
> }
>
> /*
> @@ -1144,11 +1152,155 @@ int vlv_force_gfx_clock(struct drm_i915_private *dev_priv, bool force_on)
> #undef COND
> }
>
> +static int vlv_allow_gt_wake(struct drm_i915_private *dev_priv, bool allow)
> +{
> + u32 val;
> + int err = 0;
> +
> + val = I915_READ(VLV_GTLC_WAKE_CTRL);
> + val &= ~VLV_GTLC_ALLOWWAKEREQ;
> + if (allow)
> + val |= VLV_GTLC_ALLOWWAKEREQ;
> + I915_WRITE(VLV_GTLC_WAKE_CTRL, val);
> + POSTING_READ(VLV_GTLC_WAKE_CTRL);
> +
> +#define COND (!!(I915_READ(VLV_GTLC_PW_STATUS) & VLV_GTLC_ALLOWWAKEACK) == \
> + allow)
> + err = wait_for(COND, 1);
> + if (err)
> + DRM_ERROR("timeout disabling GT waking\n");
> + return err;
> +#undef COND
> +}
> +
> +static int vlv_wait_for_gt_wells(struct drm_i915_private *dev_priv,
> + bool wait_for_on)
> +{
> + u32 mask;
> + u32 val;
> + int err;
> +
> + mask = VLV_GTLC_PW_MEDIA_STATUS_MASK | VLV_GTLC_PW_RENDER_STATUS_MASK;
> + val = wait_for_on ? mask : 0;
> +#define COND ((I915_READ(VLV_GTLC_PW_STATUS) & mask) == val)
> + if (COND)
> + return 0;
> +
> + DRM_DEBUG_KMS("waiting for GT wells to go %s (%08x)\n",
> + wait_for_on ? "on" : "off",
> + I915_READ(VLV_GTLC_PW_STATUS));
> +
> + /*
> + * RC6 transitioning can be delayed up to 2 msec (see
> + * valleyview_enable_rps), use 3 msec for safety.
> + */
> + err = wait_for(COND, 3);
> + if (err)
> + DRM_ERROR("timeout waiting for GT wells to go %s\n",
> + wait_for_on ? "on" : "off");
> +
> + return err;
> +#undef COND
> +}
> +
> +static void vlv_check_no_gt_access(struct drm_i915_private *dev_priv)
> +{
> + if (!(I915_READ(VLV_GTLC_PW_STATUS) & VLV_GTLC_ALLOWWAKEERR))
> + return;
> +
> + DRM_ERROR("GT register access while GT waking disabled\n");
> + I915_WRITE(VLV_GTLC_PW_STATUS, VLV_GTLC_ALLOWWAKEERR);
> +}
> +
> +static int vlv_runtime_suspend(struct drm_i915_private *dev_priv)
> +{
> + struct drm_device *dev = dev_priv->dev;
> + u32 mask;
> + int err;
> +
> + if (WARN_ON(!valleyview_rc6_enabled(dev)))
> + return -ENODEV;
> +
> + intel_runtime_pm_disable_interrupts(dev);
> + cancel_work_sync(&dev_priv->rps.work);
> +
> + /*
> + * Bspec defines the following GT well on flags as debug only, so
> + * don't treat them as hard failures.
> + */
> + (void)vlv_wait_for_gt_wells(dev_priv, false);
> +
> + mask = VLV_GTLC_RENDER_CTX_EXISTS | VLV_GTLC_MEDIA_CTX_EXISTS;
> + WARN_ON((I915_READ(VLV_GTLC_WAKE_CTRL) & mask) != mask);
> +
> + vlv_check_no_gt_access(dev_priv);
> +
> + err = vlv_force_gfx_clock(dev_priv, true);
> + if (err)
> + goto err1;
> +
> + err = vlv_allow_gt_wake(dev_priv, false);
> + if (err)
> + goto err2;
> + vlv_save_gunit_s0ix_state(dev_priv);
> +
> + err = vlv_force_gfx_clock(dev_priv, false);
> + if (err)
> + goto err2;
> +
> + return 0;
> +
> +err2:
> + /* For safety always re-enable waking and disable gfx clock forcing */
> + vlv_allow_gt_wake(dev_priv, true);
> +err1:
> + vlv_force_gfx_clock(dev_priv, false);
> + intel_runtime_pm_restore_interrupts(dev);
> +
> + return err;
> +}
> +
> +static int vlv_runtime_resume(struct drm_i915_private *dev_priv)
> +{
> + struct drm_device *dev = dev_priv->dev;
> + int err;
> + int ret;
> +
> + /*
> + * If any of the steps fail just try to continue, that's the best we
> + * can do at this point. Return the first error code (which will also
> + * leave RPM permanentyl disabled).
> + */
> + ret = vlv_force_gfx_clock(dev_priv, true);
> +
> + vlv_restore_gunit_s0ix_state(dev_priv);
> +
> + err = vlv_allow_gt_wake(dev_priv, true);
> + if (!ret)
> + ret = err;
> +
> + err = vlv_force_gfx_clock(dev_priv, false);
> + if (!ret)
> + ret = err;
> +
> + vlv_check_no_gt_access(dev_priv);
> +
> + intel_init_clock_gating(dev);
> + intel_reset_gt_powersave(dev);
> + i915_gem_init_swizzling(dev);
> + i915_gem_restore_fences(dev);
> +
> + intel_runtime_pm_restore_interrupts(dev);
> +
> + return ret;
> +}
> +
> static int intel_runtime_suspend(struct device *device)
> {
> struct pci_dev *pdev = to_pci_dev(device);
> struct drm_device *dev = pci_get_drvdata(pdev);
> struct drm_i915_private *dev_priv = dev->dev_private;
> + int ret = 0;
>
> if (WARN_ON_ONCE(!dev_priv->rps.enabled))
> return -ENODEV;
> @@ -1162,9 +1314,17 @@ static int intel_runtime_suspend(struct device *device)
> snb_runtime_suspend(dev_priv);
> else if (IS_HASWELL(dev) || IS_BROADWELL(dev))
> hsw_runtime_suspend(dev_priv);
You make these guys return an error code, but you don't check for
them. Even if they always return 0, I think it's good to add the check
now, because in the future someone may write a patch adding a non-zero
return and forget to add code to check for the error.
> + else if (IS_VALLEYVIEW(dev))
> + ret = vlv_runtime_suspend(dev_priv);
> else
> WARN_ON(1);
>
> + if (ret) {
> + DRM_ERROR("Runtime suspend failed, disabling it\n");
> +
> + return ret;
> + }
> +
> i915_gem_release_all_mmaps(dev_priv);
>
> del_timer_sync(&dev_priv->gpu_error.hangcheck_timer);
> @@ -1200,6 +1360,8 @@ static int intel_runtime_resume(struct device *device)
> snb_runtime_resume(dev_priv);
> else if (IS_HASWELL(dev) || IS_BROADWELL(dev))
> hsw_runtime_resume(dev_priv);
> + else if (IS_VALLEYVIEW(dev))
> + vlv_runtime_resume(dev_priv);
Same here.
> else
> WARN_ON(1);
>
> --
> 1.8.4
>
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--
Paulo Zanoni
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