diff options
Diffstat (limited to 'drivers/gpu/drm/amd/display/dc/link')
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training_8b_10b.c | 54 |
1 files changed, 36 insertions, 18 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training_8b_10b.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training_8b_10b.c index 34d2e097ca2e..5a5d48fadbf2 100644 --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training_8b_10b.c +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training_8b_10b.c @@ -35,6 +35,17 @@ #define DC_LOGGER \ link->ctx->logger +static void get_default_8b_10b_lttpr_aux_rd_interval( + union training_aux_rd_interval *training_rd_interval) +{ + /* LTTPR are required to program DPCD 0000Eh to 0x4 (16ms) upon AUX + * read reply to this register. Since old sinks with DPCD rev 1.1 + * and earlier may not support this register, assume the mandatory + * value is programmed by the LTTPR to avoid AUX timeout issues. + */ + training_rd_interval->raw = 0x4; +} + static int32_t get_cr_training_aux_rd_interval(struct dc_link *link, const struct dc_link_settings *link_settings, enum lttpr_mode lttpr_mode) @@ -43,17 +54,22 @@ static int32_t get_cr_training_aux_rd_interval(struct dc_link *link, uint32_t wait_in_micro_secs = 100; memset(&training_rd_interval, 0, sizeof(training_rd_interval)); - if (link_dp_get_encoding_format(link_settings) == DP_8b_10b_ENCODING && - link->dpcd_caps.dpcd_rev.raw >= DPCD_REV_12) { - core_link_read_dpcd( - link, - DP_TRAINING_AUX_RD_INTERVAL, - (uint8_t *)&training_rd_interval, - sizeof(training_rd_interval)); - if (lttpr_mode != LTTPR_MODE_NON_TRANSPARENT) - wait_in_micro_secs = 400; - if (training_rd_interval.bits.TRAINIG_AUX_RD_INTERVAL) - wait_in_micro_secs = training_rd_interval.bits.TRAINIG_AUX_RD_INTERVAL * 4000; + if (link_dp_get_encoding_format(link_settings) == DP_8b_10b_ENCODING) { + if (link->dpcd_caps.dpcd_rev.raw >= DPCD_REV_12) + core_link_read_dpcd( + link, + DP_TRAINING_AUX_RD_INTERVAL, + (uint8_t *)&training_rd_interval, + sizeof(training_rd_interval)); + else if (dp_is_lttpr_present(link)) + get_default_8b_10b_lttpr_aux_rd_interval(&training_rd_interval); + + if (training_rd_interval.raw != 0) { + if (lttpr_mode != LTTPR_MODE_NON_TRANSPARENT) + wait_in_micro_secs = 400; + if (training_rd_interval.bits.TRAINIG_AUX_RD_INTERVAL) + wait_in_micro_secs = training_rd_interval.bits.TRAINIG_AUX_RD_INTERVAL * 4000; + } } return wait_in_micro_secs; } @@ -71,13 +87,15 @@ static uint32_t get_eq_training_aux_rd_interval( DP_128B132B_TRAINING_AUX_RD_INTERVAL, (uint8_t *)&training_rd_interval, sizeof(training_rd_interval)); - } else if (link_dp_get_encoding_format(link_settings) == DP_8b_10b_ENCODING && - link->dpcd_caps.dpcd_rev.raw >= DPCD_REV_12) { - core_link_read_dpcd( - link, - DP_TRAINING_AUX_RD_INTERVAL, - (uint8_t *)&training_rd_interval, - sizeof(training_rd_interval)); + } else if (link_dp_get_encoding_format(link_settings) == DP_8b_10b_ENCODING) { + if (link->dpcd_caps.dpcd_rev.raw >= DPCD_REV_12) + core_link_read_dpcd( + link, + DP_TRAINING_AUX_RD_INTERVAL, + (uint8_t *)&training_rd_interval, + sizeof(training_rd_interval)); + else if (dp_is_lttpr_present(link)) + get_default_8b_10b_lttpr_aux_rd_interval(&training_rd_interval); } switch (training_rd_interval.bits.TRAINIG_AUX_RD_INTERVAL) { |