]> git.ipfire.org Git - thirdparty/kernel/stable.git/commitdiff
drm/amd/display: Initialize DAC in DCE link encoder using VBIOS
authorTimur Kristóf <timur.kristof@gmail.com>
Mon, 2 Feb 2026 11:25:05 +0000 (12:25 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 26 Feb 2026 23:01:38 +0000 (15:01 -0800)
[ Upstream commit e2a024345bce78a8e1ed7d9e84c859b05979e41e ]

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 <timur.kristof@gmail.com>
Tested-by: Mauro Rossi <issor.oruam@gmail.com>
Suggested-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/gpu/drm/amd/display/dc/bios/command_table.c
drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.c

index 76a3559f0ddc15e70dda94076a0887455842cec5..b692fa37402d9f791154f30c4305f77b80100c80 100644 (file)
@@ -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;
index 2e742950a62c7b06ff9fe1df2368eacc9896ab5f..48a1b3b492e7fbdaf68413e6f85f5ad3ab26d06b 100644 (file)
@@ -1033,6 +1033,16 @@ 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;