From e2a024345bce78a8e1ed7d9e84c859b05979e41e Mon Sep 17 00:00:00 2001 From: =?utf8?q?Timur=20Krist=C3=B3f?= Date: Mon, 2 Feb 2026 12:25:05 +0100 Subject: [PATCH] drm/amd/display: Initialize DAC in DCE link encoder using VBIOS MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The VBIOS DAC1EncoderControl() function can initialize the DAC, by writing board-specific values to certain registers. Call this at link encoder hardware initialization time similarly to how the equivalent UNIPHYTransmitterControl initialization is done. This fixes DAC output on the Radeon HD 7790. Also remove the ENCODER_CONTROL_SETUP enum from the dac_encoder_control_prepare_params function which is actually not a supported operation for DAC encoders. Fixes: 0fbe321a93ce ("drm/amd/display: Implement DCE analog link encoders (v2)") Signed-off-by: Timur Kristóf Tested-by: Mauro Rossi Suggested-by: Alex Deucher Reviewed-by: Alex Hung Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/bios/command_table.c | 3 +-- drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.c | 10 ++++++++++ 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/bios/command_table.c b/drivers/gpu/drm/amd/display/dc/bios/command_table.c index 76a3559f0ddc..b692fa37402d 100644 --- a/drivers/gpu/drm/amd/display/dc/bios/command_table.c +++ b/drivers/gpu/drm/amd/display/dc/bios/command_table.c @@ -1874,8 +1874,7 @@ static void dac_encoder_control_prepare_params( uint8_t dac_standard) { params->ucDacStandard = dac_standard; - if (action == ENCODER_CONTROL_SETUP || - action == ENCODER_CONTROL_INIT) + if (action == ENCODER_CONTROL_INIT) params->ucAction = ATOM_ENCODER_INIT; else if (action == ENCODER_CONTROL_ENABLE) params->ucAction = ATOM_ENABLE; diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.c b/drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.c index f8fcf8d1a4dd..8903bdb89c66 100644 --- a/drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.c +++ b/drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.c @@ -1036,6 +1036,16 @@ void dce110_link_encoder_hw_init( cntl.coherent = false; cntl.hpd_sel = enc110->base.hpd_source; + if (enc110->base.analog_engine != ENGINE_ID_UNKNOWN) { + result = link_dac_encoder_control(enc110, ENCODER_CONTROL_INIT, 0); + if (result != BP_RESULT_OK) { + DC_LOG_ERROR("%s: Failed to execute VBIOS command table for DAC!\n", + __func__); + BREAK_TO_DEBUGGER(); + return; + } + } + /* The code below is only applicable to encoders with a digital transmitter. */ if (enc110->base.transmitter == TRANSMITTER_UNKNOWN) return; -- 2.47.3