Re: [PATCH 5/8] drm/i915/cnl: Move voltage check into ddi buf trans functions.

Ville Syrjälä
2017-08-30T14:12:02Z

On Tue, Aug 29, 2017 at 04:22:27PM -0700, Rodrigo Vivi wrote:
> Let's start converging CNL buf translations to same style
> used on previous platforms. So first thing is to use the
> standard signature so we don't need to propagate the voltage
> check into other parts of the code, but only on the parts
> that it is really useful.
>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> ---
> drivers/gpu/drm/i915/intel_ddi.c | 48 ++++++++++++++++++----------------------
> 1 file changed, 21 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> index 506782c1a62a..7b547a7f6c2b 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -1830,9 +1830,10 @@ u8 intel_ddi_dp_voltage_max(struct intel_encoder *encoder)
> }
>
> static const struct cnl_ddi_buf_trans *
> -cnl_get_buf_trans_hdmi(struct drm_i915_private *dev_priv,
> - u32 voltage, int *n_entries)
> +cnl_get_buf_trans_hdmi(struct drm_i915_private *dev_priv, int *n_entries)
> {
> + u32 voltage = I915_READ(CNL_PORT_COMP_DW3) & VOLTAGE_INFO_MASK;

I wonder if we should just cache that somewhere. My main worry is
whether the device is always awake when we call this code.

> +
> if (voltage == VOLTAGE_INFO_0_85V) {
> *n_entries = ARRAY_SIZE(cnl_ddi_translations_hdmi_0_85V);
> return cnl_ddi_translations_hdmi_0_85V;
> @@ -1842,14 +1843,16 @@ cnl_get_buf_trans_hdmi(struct drm_i915_private *dev_priv,
> } else if (voltage == VOLTAGE_INFO_1_05V) {
> *n_entries = ARRAY_SIZE(cnl_ddi_translations_hdmi_1_05V);
> return cnl_ddi_translations_hdmi_1_05V;
> - }
> + } else
> + MISSING_CASE(voltage);

nit: Looks like these if ladders could be turned into switch statements.

Anyways, patch lgtm
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

> return NULL;
> }
>
> static const struct cnl_ddi_buf_trans *
> -cnl_get_buf_trans_dp(struct drm_i915_private *dev_priv,
> - u32 voltage, int *n_entries)
> +cnl_get_buf_trans_dp(struct drm_i915_private *dev_priv, int *n_entries)
> {
> + u32 voltage = I915_READ(CNL_PORT_COMP_DW3) & VOLTAGE_INFO_MASK;
> +
> if (voltage == VOLTAGE_INFO_0_85V) {
> *n_entries = ARRAY_SIZE(cnl_ddi_translations_dp_0_85V);
> return cnl_ddi_translations_dp_0_85V;
> @@ -1859,14 +1862,16 @@ cnl_get_buf_trans_dp(struct drm_i915_private *dev_priv,
> } else if (voltage == VOLTAGE_INFO_1_05V) {
> *n_entries = ARRAY_SIZE(cnl_ddi_translations_dp_1_05V);
> return cnl_ddi_translations_dp_1_05V;
> - }
> + } else
> + MISSING_CASE(voltage);
> return NULL;
> }
>
> static const struct cnl_ddi_buf_trans *
> -cnl_get_buf_trans_edp(struct drm_i915_private *dev_priv,
> - u32 voltage, int *n_entries)
> +cnl_get_buf_trans_edp(struct drm_i915_private *dev_priv, int *n_entries)
> {
> + u32 voltage = I915_READ(CNL_PORT_COMP_DW3) & VOLTAGE_INFO_MASK;
> +
> if (dev_priv->vbt.edp.low_vswing) {
> if (voltage == VOLTAGE_INFO_0_85V) {
> *n_entries = ARRAY_SIZE(cnl_ddi_translations_edp_0_85V);
> @@ -1877,10 +1882,11 @@ cnl_get_buf_trans_edp(struct drm_i915_private *dev_priv,
> } else if (voltage == VOLTAGE_INFO_1_05V) {
> *n_entries = ARRAY_SIZE(cnl_ddi_translations_edp_1_05V);
> return cnl_ddi_translations_edp_1_05V;
> - }
> + } else
> + MISSING_CASE(voltage);
> return NULL;
> } else {
> - return cnl_get_buf_trans_dp(dev_priv, voltage, n_entries);
> + return cnl_get_buf_trans_dp(dev_priv, n_entries);
> }
> }
>
> @@ -1888,31 +1894,19 @@ static void cnl_ddi_vswing_program(struct drm_i915_private *dev_priv,
> u32 level, enum port port, int type)
> {
> const struct cnl_ddi_buf_trans *ddi_translations = NULL;
> - u32 n_entries, val, voltage;
> + u32 n_entries, val;
> int ln;
>
> - /*
> - * Values for each port type are listed in
> - * voltage swing programming tables.
> - * Vccio voltage found in PORT_COMP_DW3.
> - */
> - voltage = I915_READ(CNL_PORT_COMP_DW3) & VOLTAGE_INFO_MASK;
> -
> if (type == INTEL_OUTPUT_HDMI) {
> - ddi_translations = cnl_get_buf_trans_hdmi(dev_priv,
> - voltage, &n_entries);
> + ddi_translations = cnl_get_buf_trans_hdmi(dev_priv, &n_entries);
> } else if (type == INTEL_OUTPUT_DP) {
> - ddi_translations = cnl_get_buf_trans_dp(dev_priv,
> - voltage, &n_entries);
> + ddi_translations = cnl_get_buf_trans_dp(dev_priv, &n_entries);
> } else if (type == INTEL_OUTPUT_EDP) {
> - ddi_translations = cnl_get_buf_trans_edp(dev_priv,
> - voltage, &n_entries);
> + ddi_translations = cnl_get_buf_trans_edp(dev_priv, &n_entries);
> }
>
> - if (ddi_translations == NULL) {
> - MISSING_CASE(voltage);
> + if (WARN_ON(ddi_translations == NULL))
> return;
> - }
>
> if (level >= n_entries) {
> DRM_DEBUG_KMS("DDI translation not found for level %d. Using %d instead.", level, n_entries - 1);
> --
> 2.13.2
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

--
Ville Syrjälä
Intel OTC