[Intel-gfx] [PATCH v2] drm/i915/vbt: update DP max link rate table

Lee, Shawn C shawn.c.lee at intel.com
Wed Feb 17 15:38:48 UTC 2021


On Wed, Feb 17, 2021 at 1:22 p.m., Ville Syrjälä wrote:
>On Wed, Feb 17, 2021 at 02:55:19PM +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.
>> 
>> v2: split the mapping table to two for old and new BDB definition.
>> 
>> Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
>> Cc: Imre Deak <imre.deak at intel.com>
>> Cc: Jani Nikula <jani.nikula at linux.intel.com>
>> Cc: Cooper Chiou <cooper.chiou at intel.com>
>> Cc: William Tseng <william.tseng at intel.com>
>> Signed-off-by: Lee Shawn C <shawn.c.lee at intel.com>
>> ---
>>  drivers/gpu/drm/i915/display/intel_bios.c     | 72 +++++++++++++++----
>>  drivers/gpu/drm/i915/display/intel_vbt_defs.h | 23 ++++--
>>  2 files changed, 74 insertions(+), 21 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c 
>> b/drivers/gpu/drm/i915/display/intel_bios.c
>> index 7902d4c2673e..a094c966f37f 100644
>> --- a/drivers/gpu/drm/i915/display/intel_bios.c
>> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
>> @@ -1759,6 +1759,58 @@ static enum port dvo_port_to_port(struct drm_i915_private *dev_priv,
>>  					  dvo_port);
>>  }
>>  
>> +static void parse_bdb_230_dp_max_link_rate(const struct child_device_config *child,
>> +					   struct ddi_vbt_port_info *info) {
>> +	switch (child->dp_max_link_rate) {
>> +	case BDB_230_VBT_DP_MAX_LINK_RATE_UHBR20:
>> +		info->dp_max_link_rate = 2000000;
>> +		break;
>> +	case BDB_230_VBT_DP_MAX_LINK_RATE_UHBR13P5:
>> +		info->dp_max_link_rate = 1350000;
>> +		break;
>> +	case BDB_230_VBT_DP_MAX_LINK_RATE_UHBR10:
>> +		info->dp_max_link_rate = 1000000;
>> +		break;
>> +	case BDB_230_VBT_DP_MAX_LINK_RATE_HBR3:
>> +		info->dp_max_link_rate = 810000;
>> +		break;
>> +	case BDB_230_VBT_DP_MAX_LINK_RATE_HBR2:
>> +		info->dp_max_link_rate = 540000;
>> +		break;
>> +	case BDB_230_VBT_DP_MAX_LINK_RATE_HBR:
>> +		info->dp_max_link_rate = 270000;
>> +		break;
>> +	case BDB_230_VBT_DP_MAX_LINK_RATE_LBR:
>> +		info->dp_max_link_rate = 162000;
>> +		break;
>> +	case BDB_230_VBT_DP_MAX_LINK_RATE_DEF:
>> +	default:
>> +		info->dp_max_link_rate = 0;
>> +		break;
>> +	}
>> +}
>> +
>> +static void parse_bdb_216_dp_max_link_rate(const struct child_device_config *child,
>> +					   struct ddi_vbt_port_info *info) {
>> +	switch (child->dp_max_link_rate) {
>> +	default:
>> +	case BDB_216_VBT_DP_MAX_LINK_RATE_HBR3:
>> +		info->dp_max_link_rate = 810000;
>> +		break;
>> +	case BDB_216_VBT_DP_MAX_LINK_RATE_HBR2:
>> +		info->dp_max_link_rate = 540000;
>> +		break;
>> +	case BDB_216_VBT_DP_MAX_LINK_RATE_HBR:
>> +		info->dp_max_link_rate = 270000;
>> +		break;
>> +	case BDB_216_VBT_DP_MAX_LINK_RATE_LBR:
>> +		info->dp_max_link_rate = 162000;
>> +		break;
>> +	}
>> +}
>
>Looks pretty good. One minor nit is that I would prefer these
>to be pure functions. Ie. they should just directly return
>the link rate instead of assigning it anywhere.
>
>Then we can just do:
>if (bdb_version >= 230)
>	info->dp_max_link_rate = parse_bdb_230_dp_max_link_rate(child)
>else
>	info->dp_max_link_rate = parse_bdb_216_dp_max_link_rate(child)
>

Just modify the code like this and send patch v3 for review. Thanks for comment!

Best regards,
Shawn

>> +
>>  static void parse_ddi_port(struct drm_i915_private *dev_priv,
>>  			   struct display_device_data *devdata,
>>  			   u8 bdb_version)
>> @@ -1884,21 +1936,11 @@ 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_HBR3:
>> -			info->dp_max_link_rate = 810000;
>> -			break;
>> -		case VBT_DP_MAX_LINK_RATE_HBR2:
>> -			info->dp_max_link_rate = 540000;
>> -			break;
>> -		case VBT_DP_MAX_LINK_RATE_HBR:
>> -			info->dp_max_link_rate = 270000;
>> -			break;
>> -		case VBT_DP_MAX_LINK_RATE_LBR:
>> -			info->dp_max_link_rate = 162000;
>> -			break;
>> -		}
>> +		if (bdb_version >= 230)
>> +			parse_bdb_230_dp_max_link_rate(child, info);
>> +		else
>> +			parse_bdb_216_dp_max_link_rate(child, info);
>> +
>>  		drm_dbg_kms(&dev_priv->drm,
>>  			    "Port %c VBT DP max link rate: %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..0d80b04b34be 100644
>> --- a/drivers/gpu/drm/i915/display/intel_vbt_defs.h
>> +++ b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
>> @@ -343,10 +343,21 @@ 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_HBR	2
>> -#define VBT_DP_MAX_LINK_RATE_LBR	3
>> +/* DP max link rate 216+ */
>> +#define BDB_216_VBT_DP_MAX_LINK_RATE_HBR3	0
>> +#define BDB_216_VBT_DP_MAX_LINK_RATE_HBR2	1
>> +#define BDB_216_VBT_DP_MAX_LINK_RATE_HBR	2
>> +#define BDB_216_VBT_DP_MAX_LINK_RATE_LBR	3
>> +
>> +/* DP max link rate 230+ */
>> +#define BDB_230_VBT_DP_MAX_LINK_RATE_DEF	0
>> +#define BDB_230_VBT_DP_MAX_LINK_RATE_LBR	1
>> +#define BDB_230_VBT_DP_MAX_LINK_RATE_HBR	2
>> +#define BDB_230_VBT_DP_MAX_LINK_RATE_HBR2	3
>> +#define BDB_230_VBT_DP_MAX_LINK_RATE_HBR3	4
>> +#define BDB_230_VBT_DP_MAX_LINK_RATE_UHBR10	5
>> +#define BDB_230_VBT_DP_MAX_LINK_RATE_UHBR13P5	6
>> +#define BDB_230_VBT_DP_MAX_LINK_RATE_UHBR20	7
>>  
>>  /*
>>   * The child device config, aka the display device data structure, 
>> provides a @@ -445,8 +456,8 @@ 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 CNL+ */
>> +	u8 dp_max_link_rate_reserved:5;				/* 230 */
>>  } __packed;
>>  
>>  struct bdb_general_definitions {
>> --
>> 2.17.1
>
>--
>Ville Syrjälä
>Intel


More information about the Intel-gfx mailing list