[Intel-gfx] [PATCH] drm/i915: Add tracking for CDCLK bypass frequency
Ville Syrjälä
ville.syrjala at linux.intel.com
Wed Jan 17 17:56:22 UTC 2018
On Wed, Jan 17, 2018 at 07:25:08PM +0200, Imre Deak wrote:
> The CDCLK bypass frequency can vary on upcoming platforms, so prepare
> for that now by tracking its value in the CDCLK state.
>
> Currently on BDW+ the bypass frequency is always the reference clock and
> I didn't bother with earlier platforms since it's not all that clear
> what's the bypass clock on those.
>
> I also didn't bother adding support for changing this frequency, since
> atm I don't see any need for it.
>
> Suggested-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Signed-off-by: Imre Deak <imre.deak at intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 2 +-
> drivers/gpu/drm/i915/intel_cdclk.c | 35 ++++++++++++++++++-----------------
> 2 files changed, 19 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index c42015b05b47..49ccfc397feb 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1791,7 +1791,7 @@ struct i915_oa_ops {
> };
>
> struct intel_cdclk_state {
> - unsigned int cdclk, vco, ref;
> + unsigned int cdclk, vco, ref, bypass;
> u8 voltage_level;
> };
>
> diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c
> index ca36321eafac..f46a61d423a1 100644
> --- a/drivers/gpu/drm/i915/intel_cdclk.c
> +++ b/drivers/gpu/drm/i915/intel_cdclk.c
> @@ -858,7 +858,7 @@ static void skl_get_cdclk(struct drm_i915_private *dev_priv,
>
> skl_dpll0_update(dev_priv, cdclk_state);
>
> - cdclk_state->cdclk = cdclk_state->ref;
> + cdclk_state->cdclk = cdclk_state->bypass = cdclk_state->ref;
My first instinct would have been to populate bypass in the PLL
readout function. I guess I just think of the bypass clock more
as a feature of the PLL. But I suppose it really doesn't matter
where we do this.
Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> if (cdclk_state->vco == 0)
> goto out;
> @@ -1006,7 +1006,7 @@ static void skl_set_cdclk(struct drm_i915_private *dev_priv,
> /* Choose frequency for this cdclk */
> switch (cdclk) {
> default:
> - WARN_ON(cdclk != dev_priv->cdclk.hw.ref);
> + WARN_ON(cdclk != dev_priv->cdclk.hw.bypass);
> WARN_ON(vco != 0);
> /* fall through */
> case 308571:
> @@ -1085,7 +1085,7 @@ static void skl_sanitize_cdclk(struct drm_i915_private *dev_priv)
>
> /* Is PLL enabled and locked ? */
> if (dev_priv->cdclk.hw.vco == 0 ||
> - dev_priv->cdclk.hw.cdclk == dev_priv->cdclk.hw.ref)
> + dev_priv->cdclk.hw.cdclk == dev_priv->cdclk.hw.bypass)
> goto sanitize;
>
> /* DPLL okay; verify the cdclock
> @@ -1159,7 +1159,7 @@ void skl_uninit_cdclk(struct drm_i915_private *dev_priv)
> {
> struct intel_cdclk_state cdclk_state = dev_priv->cdclk.hw;
>
> - cdclk_state.cdclk = cdclk_state.ref;
> + cdclk_state.cdclk = cdclk_state.bypass;
> cdclk_state.vco = 0;
> cdclk_state.voltage_level = skl_calc_voltage_level(cdclk_state.cdclk);
>
> @@ -1199,7 +1199,7 @@ static int bxt_de_pll_vco(struct drm_i915_private *dev_priv, int cdclk)
> {
> int ratio;
>
> - if (cdclk == dev_priv->cdclk.hw.ref)
> + if (cdclk == dev_priv->cdclk.hw.bypass)
> return 0;
>
> switch (cdclk) {
> @@ -1224,7 +1224,7 @@ static int glk_de_pll_vco(struct drm_i915_private *dev_priv, int cdclk)
> {
> int ratio;
>
> - if (cdclk == dev_priv->cdclk.hw.ref)
> + if (cdclk == dev_priv->cdclk.hw.bypass)
> return 0;
>
> switch (cdclk) {
> @@ -1268,7 +1268,7 @@ static void bxt_get_cdclk(struct drm_i915_private *dev_priv,
>
> bxt_de_pll_update(dev_priv, cdclk_state);
>
> - cdclk_state->cdclk = cdclk_state->ref;
> + cdclk_state->cdclk = cdclk_state->bypass = cdclk_state->ref;
>
> if (cdclk_state->vco == 0)
> goto out;
> @@ -1352,7 +1352,7 @@ static void bxt_set_cdclk(struct drm_i915_private *dev_priv,
> /* cdclk = vco / 2 / div{1,1.5,2,4} */
> switch (DIV_ROUND_CLOSEST(vco, cdclk)) {
> default:
> - WARN_ON(cdclk != dev_priv->cdclk.hw.ref);
> + WARN_ON(cdclk != dev_priv->cdclk.hw.bypass);
> WARN_ON(vco != 0);
> /* fall through */
> case 2:
> @@ -1425,7 +1425,7 @@ static void bxt_sanitize_cdclk(struct drm_i915_private *dev_priv)
> intel_dump_cdclk_state(&dev_priv->cdclk.hw, "Current CDCLK");
>
> if (dev_priv->cdclk.hw.vco == 0 ||
> - dev_priv->cdclk.hw.cdclk == dev_priv->cdclk.hw.ref)
> + dev_priv->cdclk.hw.cdclk == dev_priv->cdclk.hw.bypass)
> goto sanitize;
>
> /* DPLL okay; verify the cdclock
> @@ -1514,7 +1514,7 @@ void bxt_uninit_cdclk(struct drm_i915_private *dev_priv)
> {
> struct intel_cdclk_state cdclk_state = dev_priv->cdclk.hw;
>
> - cdclk_state.cdclk = cdclk_state.ref;
> + cdclk_state.cdclk = cdclk_state.bypass;
> cdclk_state.vco = 0;
> cdclk_state.voltage_level = bxt_calc_voltage_level(cdclk_state.cdclk);
>
> @@ -1574,7 +1574,7 @@ static void cnl_get_cdclk(struct drm_i915_private *dev_priv,
>
> cnl_cdclk_pll_update(dev_priv, cdclk_state);
>
> - cdclk_state->cdclk = cdclk_state->ref;
> + cdclk_state->cdclk = cdclk_state->bypass = cdclk_state->ref;
>
> if (cdclk_state->vco == 0)
> goto out;
> @@ -1660,7 +1660,7 @@ static void cnl_set_cdclk(struct drm_i915_private *dev_priv,
> /* cdclk = vco / 2 / div{1,2} */
> switch (DIV_ROUND_CLOSEST(vco, cdclk)) {
> default:
> - WARN_ON(cdclk != dev_priv->cdclk.hw.ref);
> + WARN_ON(cdclk != dev_priv->cdclk.hw.bypass);
> WARN_ON(vco != 0);
> /* fall through */
> case 2:
> @@ -1705,7 +1705,7 @@ static int cnl_cdclk_pll_vco(struct drm_i915_private *dev_priv, int cdclk)
> {
> int ratio;
>
> - if (cdclk == dev_priv->cdclk.hw.ref)
> + if (cdclk == dev_priv->cdclk.hw.bypass)
> return 0;
>
> switch (cdclk) {
> @@ -1732,7 +1732,7 @@ static void cnl_sanitize_cdclk(struct drm_i915_private *dev_priv)
> intel_dump_cdclk_state(&dev_priv->cdclk.hw, "Current CDCLK");
>
> if (dev_priv->cdclk.hw.vco == 0 ||
> - dev_priv->cdclk.hw.cdclk == dev_priv->cdclk.hw.ref)
> + dev_priv->cdclk.hw.cdclk == dev_priv->cdclk.hw.bypass)
> goto sanitize;
>
> /* DPLL okay; verify the cdclock
> @@ -1805,7 +1805,7 @@ void cnl_uninit_cdclk(struct drm_i915_private *dev_priv)
> {
> struct intel_cdclk_state cdclk_state = dev_priv->cdclk.hw;
>
> - cdclk_state.cdclk = cdclk_state.ref;
> + cdclk_state.cdclk = cdclk_state.bypass;
> cdclk_state.vco = 0;
> cdclk_state.voltage_level = cnl_calc_voltage_level(cdclk_state.cdclk);
>
> @@ -1846,9 +1846,10 @@ bool intel_cdclk_changed(const struct intel_cdclk_state *a,
> void intel_dump_cdclk_state(const struct intel_cdclk_state *cdclk_state,
> const char *context)
> {
> - DRM_DEBUG_DRIVER("%s %d kHz, VCO %d kHz, ref %d kHz, voltage level %d\n",
> + DRM_DEBUG_DRIVER("%s %d kHz, VCO %d kHz, ref %d kHz, bypass %d kHz, voltage level %d\n",
> context, cdclk_state->cdclk, cdclk_state->vco,
> - cdclk_state->ref, cdclk_state->voltage_level);
> + cdclk_state->ref, cdclk_state->bypass,
> + cdclk_state->voltage_level);
> }
>
> /**
> --
> 2.13.2
--
Ville Syrjälä
Intel OTC
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