drm/amd/display: Add get_dig_frontend implementation for DCEx

Some old ASICs might not implement/require get_dig_frontend helper; in
this scenario, we can have a NULL pointer exception when we try to call
it inside vbios disable operation. For example, this situation might
happen when using Polaris12 with an eDP panel. This commit avoids this
situation by adding a specific get_dig_frontend implementation for DCEx.

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Harry Wentland <Harry.Wentland@amd.com>
Cc: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Cc: Chiawen Huang <chiawen.huang@amd.com>
Reported-and-tested-by: Borislav Petkov <bp@suse.de>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

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 4592ccdfa9b037603ca17bddeee5ce5fefc2efc5..210466b2d8631f0aadec3160b969cac8897e4604 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.c
@@ -120,6 +120,7 @@ static const struct link_encoder_funcs dce110_lnk_enc_funcs = {
        .is_dig_enabled = dce110_is_dig_enabled,
        .destroy = dce110_link_encoder_destroy,
        .get_max_link_cap = dce110_link_encoder_get_max_link_cap,
+       .get_dig_frontend = dce110_get_dig_frontend,
 };
 
 static enum bp_result link_transmitter_control(
@@ -235,6 +236,44 @@ static void set_link_training_complete(
 
 }
 
+unsigned int dce110_get_dig_frontend(struct link_encoder *enc)
+{
+       struct dce110_link_encoder *enc110 = TO_DCE110_LINK_ENC(enc);
+       u32 value;
+       enum engine_id result;
+
+       REG_GET(DIG_BE_CNTL, DIG_FE_SOURCE_SELECT, &value);
+
+       switch (value) {
+       case DCE110_DIG_FE_SOURCE_SELECT_DIGA:
+               result = ENGINE_ID_DIGA;
+               break;
+       case DCE110_DIG_FE_SOURCE_SELECT_DIGB:
+               result = ENGINE_ID_DIGB;
+               break;
+       case DCE110_DIG_FE_SOURCE_SELECT_DIGC:
+               result = ENGINE_ID_DIGC;
+               break;
+       case DCE110_DIG_FE_SOURCE_SELECT_DIGD:
+               result = ENGINE_ID_DIGD;
+               break;
+       case DCE110_DIG_FE_SOURCE_SELECT_DIGE:
+               result = ENGINE_ID_DIGE;
+               break;
+       case DCE110_DIG_FE_SOURCE_SELECT_DIGF:
+               result = ENGINE_ID_DIGF;
+               break;
+       case DCE110_DIG_FE_SOURCE_SELECT_DIGG:
+               result = ENGINE_ID_DIGG;
+               break;
+       default:
+               // invalid source select DIG
+               result = ENGINE_ID_UNKNOWN;
+       }
+
+       return result;
+}
+
 void dce110_link_encoder_set_dp_phy_pattern_training_pattern(
        struct link_encoder *enc,
        uint32_t index)
@@ -1665,7 +1704,8 @@ static const struct link_encoder_funcs dce60_lnk_enc_funcs = {
        .disable_hpd = dce110_link_encoder_disable_hpd,
        .is_dig_enabled = dce110_is_dig_enabled,
        .destroy = dce110_link_encoder_destroy,
-       .get_max_link_cap = dce110_link_encoder_get_max_link_cap
+       .get_max_link_cap = dce110_link_encoder_get_max_link_cap,
+       .get_dig_frontend = dce110_get_dig_frontend
 };
 
 void dce60_link_encoder_construct(

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.h b/drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.h
index cb714a48b171c39079694895842b7d6bae6af47d..fc6ade824c231af0769a6421a0edb189545d9f00 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.h
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.h
@@ -295,6 +295,8 @@ void dce110_link_encoder_connect_dig_be_to_fe(
        enum engine_id engine,
        bool connect);
 
+unsigned int dce110_get_dig_frontend(struct link_encoder *enc);
+
 void dce110_link_encoder_set_dp_phy_pattern_training_pattern(
        struct link_encoder *enc,
        uint32_t index);