Re: [PATCH 6/8] drm/i915/skl: Turn DC handling into a power well

Imre Deak
2015-11-04T19:17:20Z

On ti, 2015-11-03 at 13:31 +0100, Patrik Jakobsson wrote:
> Handle DC off as a power well where enabling the power well will prevent
> the DMC to enter selected DC states (required around modesets and Aux
> A). Disabling the power well will allow DC states again. For now the
> highest DC state is DC6 but will be configurable in a later patch.
>
> Signed-off-by: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.c | 6 --
> drivers/gpu/drm/i915/intel_display.c | 6 ++
> drivers/gpu/drm/i915/intel_runtime_pm.c | 107 +++++++++++++++++++++-----------
> 3 files changed, 78 insertions(+), 41 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 37319b0..e190237 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -1069,9 +1069,6 @@ static int skl_suspend_complete(struct drm_i915_private *dev_priv)
> {
> skl_uninit_cdclk(dev_priv);
>
> - if (dev_priv->csr.dmc_payload)
> - skl_enable_dc6(dev_priv);
> -
> return 0;
> }
>
> @@ -1116,9 +1113,6 @@ static int bxt_resume_prepare(struct drm_i915_private *dev_priv)
>
> static int skl_resume_prepare(struct drm_i915_private *dev_priv)
> {
> - if (dev_priv->csr.dmc_payload)
> - skl_disable_dc6(dev_priv);
> -
> skl_init_cdclk(dev_priv);
> intel_csr_load_program(dev_priv);
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index c6d60b8..e401871 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -13296,6 +13296,9 @@ static int intel_atomic_commit(struct drm_device *dev,
> to_intel_crtc_state(crtc->state)->update_pipe;
> unsigned long put_domains = 0;
>
> + if (modeset)
> + intel_display_power_get(dev_priv, POWER_DOMAIN_MODESET);
> +
> if (modeset && crtc->state->active) {
> update_scanline_offset(to_intel_crtc(crtc));
> dev_priv->display.crtc_enable(crtc);
> @@ -13319,6 +13322,9 @@ static int intel_atomic_commit(struct drm_device *dev,
> modeset_put_power_domains(dev_priv, put_domains);
>
> intel_post_plane_update(intel_crtc);
> +
> + if (modeset)
> + intel_display_power_put(dev_priv, POWER_DOMAIN_MODESET);
> }
>
> /* FIXME: add subpixel order */
> diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
> index c901b19..042d92f 100644
> --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> @@ -49,9 +49,6 @@
> * present for a given platform.
> */
>
> -#define GEN9_ENABLE_DC5(dev) 0
> -#define SKL_ENABLE_DC6(dev) IS_SKYLAKE(dev)
> -
> #define for_each_power_well(i, power_well, domain_mask, power_domains) \
> for (i = 0; \
> i < (power_domains)->power_well_count && \
> @@ -336,10 +333,15 @@ static void hsw_set_power_well(struct drm_i915_private *dev_priv,
> SKL_DISPLAY_POWERWELL_1_POWER_DOMAINS | \
> BIT(POWER_DOMAIN_PLLS) | \
> BIT(POWER_DOMAIN_INIT))
> +#define SKL_DISPLAY_DC_OFF_POWER_DOMAINS ( \
> + BIT(POWER_DOMAIN_MODESET) | \
> + BIT(POWER_DOMAIN_AUX_A) | \
> + BIT(POWER_DOMAIN_INIT))
> #define SKL_DISPLAY_ALWAYS_ON_POWER_DOMAINS ( \
> (POWER_DOMAIN_MASK & ~(SKL_DISPLAY_POWERWELL_1_POWER_DOMAINS | \
> SKL_DISPLAY_POWERWELL_2_POWER_DOMAINS | \
> - SKL_DISPLAY_MISC_IO_POWER_DOMAINS)) | \
> + SKL_DISPLAY_MISC_IO_POWER_DOMAINS | \
> + SKL_DISPLAY_DC_OFF_POWER_DOMAINS)) | \
> BIT(POWER_DOMAIN_INIT))
>
> #define BXT_DISPLAY_POWERWELL_2_POWER_DOMAINS ( \
> @@ -511,20 +513,6 @@ static void gen9_enable_dc5(struct drm_i915_private *dev_priv)
> POSTING_READ(DC_STATE_EN);
> }
>
> -static void gen9_disable_dc5(struct drm_i915_private *dev_priv)
> -{
> - uint32_t val;
> -
> - assert_can_disable_dc5(dev_priv);
> -
> - DRM_DEBUG_KMS("Disabling DC5\n");
> -
> - val = I915_READ(DC_STATE_EN);
> - val &= ~DC_STATE_EN_UPTO_DC5;
> - I915_WRITE(DC_STATE_EN, val);
> - POSTING_READ(DC_STATE_EN);
> -}
> -
> static void assert_can_enable_dc6(struct drm_i915_private *dev_priv)
> {
> struct drm_device *dev = dev_priv->dev;
> @@ -553,6 +541,21 @@ static void assert_can_disable_dc6(struct drm_i915_private *dev_priv)
> "DC6 already programmed to be disabled.\n");
> }
>
> +static void gen9_disable_dc5_dc6(struct drm_i915_private *dev_priv)
> +{
> + uint32_t val;
> +
> + assert_can_disable_dc5(dev_priv);
> + assert_can_disable_dc6(dev_priv);
> +
> + DRM_DEBUG_KMS("Disabling DC5 and DC6\n");
> +
> + val = I915_READ(DC_STATE_EN);
> + val &= ~DC_STATE_EN_UPTO_DC5_DC6_MASK;
> + I915_WRITE(DC_STATE_EN, val);
> + POSTING_READ(DC_STATE_EN);
> +}
> +
> void skl_enable_dc6(struct drm_i915_private *dev_priv)
> {
> uint32_t val;
> @@ -632,17 +635,13 @@ static void skl_set_power_well(struct drm_i915_private *dev_priv,
> "Invalid for power well status to be enabled, unless done by the BIOS, \
> when request is to disable!\n");
> if (power_well->data == SKL_DISP_PW_2) {
> - if (GEN9_ENABLE_DC5(dev))
> - gen9_disable_dc5(dev_priv);
> - if (SKL_ENABLE_DC6(dev)) {
> - /*
> - * DDI buffer programming unnecessary during driver-load/resume
> - * as it's already done during modeset initialization then.
> - * It's also invalid here as encoder list is still uninitialized.
> - */
> - if (!dev_priv->power_domains.initializing)
> - intel_prepare_ddi(dev);
> - }
> + /*
> + * DDI buffer programming unnecessary during driver-load/resume
> + * as it's already done during modeset initialization then.
> + * It's also invalid here as encoder list is still uninitialized.
> + */
> + if (!dev_priv->power_domains.initializing)
> + intel_prepare_ddi(dev);
> }
> I915_WRITE(HSW_PWR_WELL_DRIVER, tmp | req_mask);
> }
> @@ -658,17 +657,13 @@ static void skl_set_power_well(struct drm_i915_private *dev_priv,
> } else {
> if (enable_requested) {
> if (IS_SKYLAKE(dev) &&
> - (power_well->data == SKL_DISP_PW_1))
> + (power_well->data == SKL_DISP_PW_1)) {
> DRM_DEBUG_KMS("Not Disabling PW1, dmc will handle\n");
> - else {
> + } else {
> I915_WRITE(HSW_PWR_WELL_DRIVER, tmp & ~req_mask);
> POSTING_READ(HSW_PWR_WELL_DRIVER);
> DRM_DEBUG_KMS("Disabling %s\n", power_well->name);
> }
> -
> - if (GEN9_ENABLE_DC5(dev) &&
> - power_well->data == SKL_DISP_PW_2)
> - gen9_enable_dc5(dev_priv);
> }
> }
>
> @@ -743,6 +738,36 @@ static void skl_power_well_disable(struct drm_i915_private *dev_priv,
> skl_set_power_well(dev_priv, power_well, false);
> }
>
> +static bool skl_dc_off_power_well_enabled(struct drm_i915_private *dev_priv,
> + struct i915_power_well *power_well)
> +{
> + return !(I915_READ(DC_STATE_EN) & DC_STATE_EN_UPTO_DC6);
> +}
> +
> +static void skl_dc_off_power_well_enable(struct drm_i915_private *dev_priv,
> + struct i915_power_well *power_well)
> +{
> + gen9_disable_dc5_dc6(dev_priv);
> +}
> +
> +static void skl_dc_off_power_well_disable(struct drm_i915_private *dev_priv,
> + struct i915_power_well *power_well)
> +{
> + if (IS_SKYLAKE(dev_priv))
> + skl_enable_dc6(dev_priv);
> + else
> + gen9_enable_dc5(dev_priv);
> +}
> +
> +static void skl_dc_off_power_well_sync_hw(struct drm_i915_private *dev_priv,
> + struct i915_power_well *power_well)
> +{
> + if (power_well->count > 0)
> + skl_dc_off_power_well_enable(dev_priv, power_well);
> + else
> + skl_dc_off_power_well_disable(dev_priv, power_well);
> +}
> +
> static void i9xx_always_on_power_well_noop(struct drm_i915_private *dev_priv,
> struct i915_power_well *power_well)
> {
> @@ -1574,6 +1599,13 @@ static const struct i915_power_well_ops skl_power_well_ops = {
> .is_enabled = skl_power_well_enabled,
> };
>
> +static const struct i915_power_well_ops skl_dc_off_power_well_ops = {
> + .sync_hw = skl_dc_off_power_well_sync_hw,
> + .enable = skl_dc_off_power_well_enable,
> + .disable = skl_dc_off_power_well_disable,
> + .is_enabled = skl_dc_off_power_well_enabled,
> +};
> +
> static struct i915_power_well hsw_power_wells[] = {
> {
> .name = "always-on",
> @@ -1738,6 +1770,11 @@ static struct i915_power_well skl_power_wells[] = {
> .data = SKL_DISP_PW_1,
> },
> {
> + .name = "DC off",
> + .domains = SKL_DISPLAY_DC_OFF_POWER_DOMAINS,
> + .ops = &skl_dc_off_power_well_ops,

We need to set a unique ID in .data, since we use it to look up power
wells. I have a patch to fix up the other places missing an ID, but you
could fix this one up already now.

> + },
> + {
> .name = "MISC IO power well",
> .domains = SKL_DISPLAY_MISC_IO_POWER_DOMAINS,
> .ops = &skl_power_well_ops,