From: George Shen Date: Tue, 4 Feb 2025 19:34:02 +0000 (-0500) Subject: drm/amd/display: Read LTTPR ALPM caps during link cap retrieval X-Git-Tag: v6.15-rc1~120^2~17^2~17 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=de84d580126eb2214937df755cfec5ef0901479e;p=thirdparty%2Fkernel%2Flinux.git drm/amd/display: Read LTTPR ALPM caps during link cap retrieval [Why] The latest DP spec requires the DP TX to read DPCD F0000h through F0009h when detecting LTTPR capabilities for the first time. [How] Update LTTPR cap retrieval to read up to F0009h (two more bytes than the previous F0007h), and store the LTTPR ALPM capabilities. Reviewed-by: Wenjing Liu Signed-off-by: George Shen Signed-off-by: Roman Li Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher --- diff --git a/drivers/gpu/drm/amd/display/dc/dc_dp_types.h b/drivers/gpu/drm/amd/display/dc/dc_dp_types.h index 94ce8fe744810..ae6e2d8552acf 100644 --- a/drivers/gpu/drm/amd/display/dc/dc_dp_types.h +++ b/drivers/gpu/drm/amd/display/dc/dc_dp_types.h @@ -959,6 +959,14 @@ union dp_128b_132b_supported_lttpr_link_rates { uint8_t raw; }; +union dp_alpm_lttpr_cap { + struct { + uint8_t AUX_LESS_ALPM_SUPPORTED :1; + uint8_t RESERVED :7; + } bits; + uint8_t raw; +}; + union dp_sink_video_fallback_formats { struct { uint8_t dp_1024x768_60Hz_24bpp_support :1; @@ -1118,6 +1126,7 @@ struct dc_lttpr_caps { uint8_t max_ext_timeout; union dp_main_link_channel_coding_lttpr_cap main_link_channel_coding; union dp_128b_132b_supported_lttpr_link_rates supported_128b_132b_rates; + union dp_alpm_lttpr_cap alpm; uint8_t aux_rd_interval[MAX_REPEATER_CNT - 1]; }; @@ -1370,6 +1379,9 @@ struct dp_trace { #ifndef DPCD_MAX_UNCOMPRESSED_PIXEL_RATE_CAP #define DPCD_MAX_UNCOMPRESSED_PIXEL_RATE_CAP 0x221c #endif +#ifndef DP_LTTPR_ALPM_CAPABILITIES +#define DP_LTTPR_ALPM_CAPABILITIES 0xF0009 +#endif #ifndef DP_REPEATER_CONFIGURATION_AND_STATUS_SIZE #define DP_REPEATER_CONFIGURATION_AND_STATUS_SIZE 0x50 #endif diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c index 44c3023a77318..80439224acca0 100644 --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c @@ -1502,7 +1502,7 @@ static bool dpcd_read_sink_ext_caps(struct dc_link *link) enum dc_status dp_retrieve_lttpr_cap(struct dc_link *link) { - uint8_t lttpr_dpcd_data[8] = {0}; + uint8_t lttpr_dpcd_data[10] = {0}; enum dc_status status; bool is_lttpr_present; @@ -1552,6 +1552,10 @@ enum dc_status dp_retrieve_lttpr_cap(struct dc_link *link) lttpr_dpcd_data[DP_PHY_REPEATER_128B132B_RATES - DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV]; + link->dpcd_caps.lttpr_caps.alpm.raw = + lttpr_dpcd_data[DP_LTTPR_ALPM_CAPABILITIES - + DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV]; + /* If this chip cap is set, at least one retimer must exist in the chain * Override count to 1 if we receive a known bad count (0 or an invalid value) */ if (((link->chip_caps & AMD_EXT_DISPLAY_PATH_CAPS__EXT_CHIP_MASK) == AMD_EXT_DISPLAY_PATH_CAPS__DP_FIXED_VS_EN) &&