[PATCH 5.14 016/151] drm/amd/display: Fix detection of 4 lane for DPALT

Greg Kroah-Hartman
2021-10-11T13:59:47Z

From: Hansen <Hansen.Dsouza@amd.com>

commit 5a1fef027846e7635b9d320b2cc0b416fd11a3be upstream.

[Why]
DPALT detection for B0 PHY has its own set of RDPCSPIPE registers

[How]
Use RDPCSPIPE registers to detect if DPALT lane is 4 lane

Reviewed-by: Charlene Liu <Charlene.Liu@amd.com>
Acked-by: Solomon Chiu <solomon.chiu@amd.com>
Signed-off-by: Hansen <Hansen.Dsouza@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/amd/display/dc/dcn31/dcn31_dio_link_encoder.c | 33 +++++++++-
drivers/gpu/drm/amd/display/dc/dcn31/dcn31_dio_link_encoder.h | 3
2 files changed, 35 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_dio_link_encoder.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_dio_link_encoder.c
@@ -63,6 +63,10 @@
#define AUX_REG_WRITE(reg_name, val) \
dm_write_reg(CTX, AUX_REG(reg_name), val)

+#ifndef MIN
+#define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
+#endif
+
void dcn31_link_encoder_set_dio_phy_mux(
struct link_encoder *enc,
enum encoder_type_select sel,
@@ -217,7 +221,7 @@ static const struct link_encoder_funcs d
.get_dig_frontend = dcn10_get_dig_frontend,
.get_dig_mode = dcn10_get_dig_mode,
.is_in_alt_mode = dcn31_link_encoder_is_in_alt_mode,
- .get_max_link_cap = dcn20_link_encoder_get_max_link_cap,
+ .get_max_link_cap = dcn31_link_encoder_get_max_link_cap,
.set_dio_phy_mux = dcn31_link_encoder_set_dio_phy_mux,
};

@@ -435,3 +439,30 @@ bool dcn31_link_encoder_is_in_alt_mode(s

return is_usb_c_alt_mode;
}
+
+void dcn31_link_encoder_get_max_link_cap(struct link_encoder *enc,
+ struct dc_link_settings *link_settings)
+{
+ struct dcn10_link_encoder *enc10 = TO_DCN10_LINK_ENC(enc);
+ uint32_t is_in_usb_c_dp4_mode = 0;
+
+ dcn10_link_encoder_get_max_link_cap(enc, link_settings);
+
+ /* in usb c dp2 mode, max lane count is 2 */
+ if (enc->funcs->is_in_alt_mode && enc->funcs->is_in_alt_mode(enc)) {
+ if (enc->ctx->asic_id.hw_internal_rev != YELLOW_CARP_B0) {
+ // [Note] no need to check hw_internal_rev once phy mux selection is ready
+ REG_GET(RDPCSTX_PHY_CNTL6, RDPCS_PHY_DPALT_DP4, &is_in_usb_c_dp4_mode);
+ } else {
+ if ((enc10->base.transmitter == TRANSMITTER_UNIPHY_A)
+ || (enc10->base.transmitter == TRANSMITTER_UNIPHY_B)
+ || (enc10->base.transmitter == TRANSMITTER_UNIPHY_E)) {
+ REG_GET(RDPCSTX_PHY_CNTL6, RDPCS_PHY_DPALT_DP4, &is_in_usb_c_dp4_mode);
+ } else {
+ REG_GET(RDPCSPIPE_PHY_CNTL6, RDPCS_PHY_DPALT_DP4, &is_in_usb_c_dp4_mode);
+ }
+ }
+ if (!is_in_usb_c_dp4_mode)
+ link_settings->lane_count = MIN(LANE_COUNT_TWO, link_settings->lane_count);
+ }
+}
--- a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_dio_link_encoder.h
+++ b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_dio_link_encoder.h
@@ -252,4 +252,7 @@ void dcn31_link_encoder_disable_output(
bool dcn31_link_encoder_is_in_alt_mode(
struct link_encoder *enc);

+void dcn31_link_encoder_get_max_link_cap(struct link_encoder *enc,
+ struct dc_link_settings *link_settings);
+
#endif /* __DC_LINK_ENCODER__DCN31_H__ */