On Mon, Feb 01, 2021 at 11:02:28PM +0800, Lee Shawn C wrote:
> According to Bspec #20124, max link rate table for DP was updated
> at BDB version 230. Max link rate can support upto UHBR.
>
> After migrate to BDB v230, the definition for LBR, HBR2 and HBR3
> were changed. For backward compatibility. If BDB version was
> from 216 to 229. Driver have to follow original rule to configure
> DP max link rate value from VBT.
>
> Cc: Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx>
> Cc: Imre Deak <imre.deak@xxxxxxxxx>
> Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
> Cc: Cooper Chiou <cooper.chiou@xxxxxxxxx>
> Cc: William Tseng <william.tseng@xxxxxxxxx>
> Signed-off-by: Lee Shawn C <shawn.c.lee@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_bios.c | 24 ++++++++++++++++++-
> drivers/gpu/drm/i915/display/intel_vbt_defs.h | 14 +++++++----
> 2 files changed, 32 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
> index 04337ac6f8c4..be1f732e6550 100644
> --- a/drivers/gpu/drm/i915/display/intel_bios.c
> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
> @@ -1876,7 +1876,15 @@ static void parse_ddi_port(struct drm_i915_private *dev_priv,
> /* DP max link rate for CNL+ */
> if (bdb_version >= 216) {
> switch (child->dp_max_link_rate) {
> - default:
> + case VBT_DP_MAX_LINK_RATE_UHBR20:
> + info->dp_max_link_rate = 2000000;
> + break;
> + case VBT_DP_MAX_LINK_RATE_UHBR13P5:
> + info->dp_max_link_rate = 1350000;
> + break;
> + case VBT_DP_MAX_LINK_RATE_UHBR10:
> + info->dp_max_link_rate = 1000000;
> + break;
> case VBT_DP_MAX_LINK_RATE_HBR3:
> info->dp_max_link_rate = 810000;
> break;
> @@ -1889,7 +1897,21 @@ static void parse_ddi_port(struct drm_i915_private *dev_priv,
> case VBT_DP_MAX_LINK_RATE_LBR:
> info->dp_max_link_rate = 162000;
> break;
> + case VBT_DP_MAX_LINK_RATE_DEFAULT:
> + default:
> + info->dp_max_link_rate = 0;
> + break;
> + }
> +
> + if (bdb_version < 230) {
> + if (child->dp_max_link_rate == VBT_DP_MAX_LINK_RATE_DEFAULT)
> + info->dp_max_link_rate = 810000;
> + else if (child->dp_max_link_rate == VBT_DP_MAX_LINK_RATE_LBR)
> + info->dp_max_link_rate = 540000;
> + else if (child->dp_max_link_rate == VBT_DP_MAX_LINK_RATE_HBR2)
> + info->dp_max_link_rate = 162000;
> }
I would split this into two separate functions, one does the new
mapping, the other the old mapping.
> +
> drm_dbg_kms(&dev_priv->drm,
> "VBT DP max link rate for port %c: %d\n",
> port_name(port), info->dp_max_link_rate);
> diff --git a/drivers/gpu/drm/i915/display/intel_vbt_defs.h b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> index 6d10fa037751..578a54b33f32 100644
> --- a/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> +++ b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> @@ -343,10 +343,14 @@ enum vbt_gmbus_ddi {
> #define DP_AUX_H 0x80
> #define DP_AUX_I 0x90
>
> -#define VBT_DP_MAX_LINK_RATE_HBR3 0
> -#define VBT_DP_MAX_LINK_RATE_HBR2 1
> +#define VBT_DP_MAX_LINK_RATE_DEFAULT 0
> +#define VBT_DP_MAX_LINK_RATE_LBR 1
> #define VBT_DP_MAX_LINK_RATE_HBR 2
> -#define VBT_DP_MAX_LINK_RATE_LBR 3
> +#define VBT_DP_MAX_LINK_RATE_HBR2 3
> +#define VBT_DP_MAX_LINK_RATE_HBR3 4
> +#define VBT_DP_MAX_LINK_RATE_UHBR10 5
> +#define VBT_DP_MAX_LINK_RATE_UHBR13P5 6
> +#define VBT_DP_MAX_LINK_RATE_UHBR20 7
And we should keep both old and new names for these.
Sadly I can't right now check the spec since it no longer has the
old stuff apparently, and the VBT section got moved around so the
history no longer shows anything either :( I'll have to pull the whole
thing down I guess so I can double check against the old version.
>
> /*
> * The child device config, aka the display device data structure, provides a
> @@ -445,8 +449,8 @@ struct child_device_config {
> u16 dp_gpio_pin_num; /* 195 */
> u8 dp_iboost_level:4; /* 196 */
> u8 hdmi_iboost_level:4; /* 196 */
> - u8 dp_max_link_rate:2; /* 216 CNL+ */
> - u8 dp_max_link_rate_reserved:6; /* 216 */
> + u8 dp_max_link_rate:3; /* 230 */
> + u8 dp_max_link_rate_reserved:5; /* 230 */
> } __packed;
>
> struct bdb_general_definitions {
> --
> 2.17.1
--
Ville Syrjälä
Intel
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