Re: [PATCH v2] drm/i915: Per-DDI I_boost override

["Antti Koskipää" <antti.koskipaa@linux.intel.com>]

On 07/03/2015 06:09 PM, Paulo Zanoni wrote:
> 2015-07-03 8:28 GMT-03:00 Antti Koskipaa <antti.koskipaa@linux.intel.com>:
>> An OEM may request increased I_boost beyond the recommended values
>> by specifying an I_boost value to be applied to all swing entries for
>> a port. These override values are specified in VBT.
>>
>> v2: rebase and remove unused iboost_bit variable
>>
>> Issue: VIZ-5676
>> Signed-off-by: Antti Koskipaa <antti.koskipaa@linux.intel.com>
>> ---
>>  drivers/gpu/drm/i915/i915_drv.h   |  3 +++
>>  drivers/gpu/drm/i915/intel_bios.c | 21 +++++++++++++++++++++
>>  drivers/gpu/drm/i915/intel_bios.h |  9 +++++++++
>>  drivers/gpu/drm/i915/intel_ddi.c  | 38 ++++++++++++++++++++++++++++++--------
>>  4 files changed, 63 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>> index 1dbd957..6aa8083 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -1410,6 +1410,9 @@ struct ddi_vbt_port_info {
>>         uint8_t supports_dvi:1;
>>         uint8_t supports_hdmi:1;
>>         uint8_t supports_dp:1;
>> +
>> +       uint8_t dp_boost_level;
>> +       uint8_t hdmi_boost_level;
>>  };
>>
>>  enum psr_lines_to_wait {
>> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
>> index 2ff9eb0..76e12f5 100644
>> --- a/drivers/gpu/drm/i915/intel_bios.c
>> +++ b/drivers/gpu/drm/i915/intel_bios.c
>> @@ -886,6 +886,17 @@ err:
>>         memset(dev_priv->vbt.dsi.sequence, 0, sizeof(dev_priv->vbt.dsi.sequence));
>>  }
>>
>> +static u8 translate_iboost(u8 val)
>> +{
>> +       static const u8 mapping[] = { 1, 3, 7 }; /* See VBT spec */
>> +
>> +       if (val >= ARRAY_SIZE(mapping)) {
>> +               DRM_DEBUG_KMS("Unsupported I_boost value found in VBT (%d), display may not work properly\n", val);
>> +               return 0;
>> +       }
>> +       return mapping[val];
>> +}
>> +
>>  static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,
>>                            const struct bdb_header *bdb)
>>  {
>> @@ -986,6 +997,16 @@ static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,
>>                               hdmi_level_shift);
>>                 info->hdmi_level_shift = hdmi_level_shift;
>>         }
>> +
>> +       /* Parse the I_boost config for SKL and above */
>> +       if (bdb->version >= 196 && (child->common.flags_1 & IBOOST_ENABLE)) {
>> +               info->dp_boost_level = translate_iboost(child->common.iboost_level & 0xF);
>> +               DRM_DEBUG_KMS("VBT (e)DP boost level for port %c: %d\n",
>> +                             port_name(port), info->dp_boost_level);
>> +               info->hdmi_boost_level = translate_iboost(child->common.iboost_level >> 4);
>> +               DRM_DEBUG_KMS("VBT HDMI boost level for port %c: %d\n",
>> +                             port_name(port), info->hdmi_boost_level);
>> +       }
>>  }
>>
>>  static void parse_ddi_ports(struct drm_i915_private *dev_priv,
>> diff --git a/drivers/gpu/drm/i915/intel_bios.h b/drivers/gpu/drm/i915/intel_bios.h
>> index af0b476..8edd75c 100644
>> --- a/drivers/gpu/drm/i915/intel_bios.h
>> +++ b/drivers/gpu/drm/i915/intel_bios.h
>> @@ -231,6 +231,10 @@ struct old_child_dev_config {
>>  /* This one contains field offsets that are known to be common for all BDB
>>   * versions. Notice that the meaning of the contents contents may still change,
>>   * but at least the offsets are consistent. */
>> +
>> +/* Definitions for flags_1 */
>> +#define IBOOST_ENABLE (1<<3)
>> +
>>  struct common_child_dev_config {
>>         u16 handle;
>>         u16 device_type;
>> @@ -239,8 +243,13 @@ struct common_child_dev_config {
>>         u8 not_common2[2];
>>         u8 ddc_pin;
>>         u16 edid_ptr;
>> +       u8 obsolete;
>> +       u8 flags_1;
>> +       u8 not_common3[13];
>> +       u8 iboost_level;
> 
> In the old VBT spec I have, each child_dev_config is supposed to have
> only 33 bytes. But in this patch you're increasing it to 38. I believe
> this is what's causing the errors I see when I boot my BDW.
> 
> Are you sure they increased the VBT's ChildDevInfo to more than 33
> bytes? I don't have access to your VBT spec right now, so I can't do a
> proper review or a suggestion on how to fix the problem.

The VBT spec I coded for does increase the size. You need to look at
version >= 196 of the spec.

>>  } __packed;
>>
>> +
>>  /* This field changes depending on the BDB version, so the most reliable way to
>>   * read it is by checking the BDB version and reading the raw pointer. */
>>  union child_device_config {
>> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
>> index 15fc66a..c83f15f 100644
>> --- a/drivers/gpu/drm/i915/intel_ddi.c
>> +++ b/drivers/gpu/drm/i915/intel_ddi.c
>> @@ -440,6 +440,7 @@ static void intel_prepare_ddi_buffers(struct drm_device *dev, enum port port,
>>  {
>>         struct drm_i915_private *dev_priv = dev->dev_private;
>>         u32 reg;
>> +       u32 iboost_bit = 0;
>>         int i, n_hdmi_entries, n_dp_entries, n_edp_entries, hdmi_default_entry,
>>             size;
>>         int hdmi_level = dev_priv->vbt.ddi_port_info[port].hdmi_level_shift;
>> @@ -465,6 +466,10 @@ static void intel_prepare_ddi_buffers(struct drm_device *dev, enum port port,
>>                 ddi_translations_hdmi =
>>                                 skl_get_buf_trans_hdmi(dev, &n_hdmi_entries);
>>                 hdmi_default_entry = 8;
>> +               /* If we're boosting the current, set bit 31 of trans1 */
>> +               if (dev_priv->vbt.ddi_port_info[port].hdmi_boost_level ||
>> +                   dev_priv->vbt.ddi_port_info[port].dp_boost_level)
>> +                       iboost_bit = 1<<31;
>>         } else if (IS_BROADWELL(dev)) {
>>                 ddi_translations_fdi = bdw_ddi_translations_fdi;
>>                 ddi_translations_dp = bdw_ddi_translations_dp;
>> @@ -525,7 +530,7 @@ static void intel_prepare_ddi_buffers(struct drm_device *dev, enum port port,
>>         }
>>
>>         for (i = 0, reg = DDI_BUF_TRANS(port); i < size; i++) {
>> -               I915_WRITE(reg, ddi_translations[i].trans1);
>> +               I915_WRITE(reg, ddi_translations[i].trans1 | iboost_bit);
>>                 reg += 4;
>>                 I915_WRITE(reg, ddi_translations[i].trans2);
>>                 reg += 4;
>> @@ -540,7 +545,7 @@ static void intel_prepare_ddi_buffers(struct drm_device *dev, enum port port,
>>                 hdmi_level = hdmi_default_entry;
>>
>>         /* Entry 9 is for HDMI: */
>> -       I915_WRITE(reg, ddi_translations_hdmi[hdmi_level].trans1);
>> +       I915_WRITE(reg, ddi_translations_hdmi[hdmi_level].trans1 | iboost_bit);
>>         reg += 4;
>>         I915_WRITE(reg, ddi_translations_hdmi[hdmi_level].trans2);
>>         reg += 4;
>> @@ -2083,18 +2088,35 @@ static void skl_ddi_set_iboost(struct drm_device *dev, u32 level,
>>         struct drm_i915_private *dev_priv = dev->dev_private;
>>         const struct ddi_buf_trans *ddi_translations;
>>         uint8_t iboost;
>> +       uint8_t dp_iboost, hdmi_iboost;
>>         int n_entries;
>>         u32 reg;
>>
>> +       /* VBT may override standard boost values */
>> +       dp_iboost = dev_priv->vbt.ddi_port_info[port].dp_boost_level;
>> +       hdmi_iboost = dev_priv->vbt.ddi_port_info[port].hdmi_boost_level;
>> +
>>         if (type == INTEL_OUTPUT_DISPLAYPORT) {
>> -               ddi_translations = skl_get_buf_trans_dp(dev, &n_entries);
>> -               iboost = ddi_translations[port].i_boost;
>> +               if (dp_iboost) {
>> +                       iboost = dp_iboost;
>> +               } else {
>> +                       ddi_translations = skl_get_buf_trans_dp(dev, &n_entries);
>> +                       iboost = ddi_translations[port].i_boost;
>> +               }
>>         } else if (type == INTEL_OUTPUT_EDP) {
>> -               ddi_translations = skl_get_buf_trans_edp(dev, &n_entries);
>> -               iboost = ddi_translations[port].i_boost;
>> +               if (dp_iboost) {
>> +                       iboost = dp_iboost;
>> +               } else {
>> +                       ddi_translations = skl_get_buf_trans_edp(dev, &n_entries);
>> +                       iboost = ddi_translations[port].i_boost;
>> +               }
>>         } else if (type == INTEL_OUTPUT_HDMI) {
>> -               ddi_translations = skl_get_buf_trans_hdmi(dev, &n_entries);
>> -               iboost = ddi_translations[port].i_boost;
>> +               if (hdmi_iboost) {
>> +                       iboost = hdmi_iboost;
>> +               } else {
>> +                       ddi_translations = skl_get_buf_trans_hdmi(dev, &n_entries);
>> +                       iboost = ddi_translations[port].i_boost;
>> +               }
>>         } else {
>>                 return;
>>         }
>> --
>> 1.8.1.5
>>
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> 
> 
> 

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