[PATCH 27/46] drm/amd/display: Add trigger FIFO resync path for DCN35

[Wayne Lin]

From: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>

[Why]
FIFO error can occur if we don't trigger a DISPCLK change after
touching K1/K2 dividers. For 4k144 eDP + hotplug of USB-C DP display
we see FIFO underflow.

[How]
We have the path to trigger the resync as the workaround in
DCN314/DCN32, it just needs to be ported over to DCN35.

Reviewed-by: Charlene Liu <charlene.liu at amd.com>
Acked-by: Wayne Lin <wayne.lin at amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>
---
 drivers/gpu/drm/amd/display/dc/dcn35/dcn35_dccg.c      | 10 ++++++++++
 drivers/gpu/drm/amd/display/dc/hwss/dcn35/dcn35_init.c |  2 ++
 2 files changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn35/dcn35_dccg.c b/drivers/gpu/drm/amd/display/dc/dcn35/dcn35_dccg.c
index 4c53e339e325..4b282b7e0996 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn35/dcn35_dccg.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn35/dcn35_dccg.c
@@ -41,6 +41,15 @@
 #define DC_LOGGER \
 	dccg->ctx->logger
 
+static void dccg35_trigger_dio_fifo_resync(struct dccg *dccg)
+{
+	struct dcn_dccg *dccg_dcn = TO_DCN_DCCG(dccg);
+	uint32_t dispclk_rdivider_value = 0;
+
+	REG_GET(DENTIST_DISPCLK_CNTL, DENTIST_DISPCLK_RDIVIDER, &dispclk_rdivider_value);
+	REG_UPDATE(DENTIST_DISPCLK_CNTL, DENTIST_DISPCLK_WDIVIDER, dispclk_rdivider_value);
+}
+
 static void dcn35_set_dppclk_enable(struct dccg *dccg,
 				 uint32_t dpp_inst, uint32_t enable)
 {
@@ -1056,6 +1065,7 @@ static const struct dccg_funcs dccg35_funcs = {
 	.enable_dsc = dccg35_enable_dscclk,
 	.set_pixel_rate_div = dccg35_set_pixel_rate_div,
 	.get_pixel_rate_div = dccg35_get_pixel_rate_div,
+	.trigger_dio_fifo_resync = dccg35_trigger_dio_fifo_resync,
 	.set_valid_pixel_rate = dccg35_set_valid_pixel_rate,
 	.enable_symclk_se = dccg35_enable_symclk_se,
 	.disable_symclk_se = dccg35_disable_symclk_se,
diff --git a/drivers/gpu/drm/amd/display/dc/hwss/dcn35/dcn35_init.c b/drivers/gpu/drm/amd/display/dc/hwss/dcn35/dcn35_init.c
index 7ed5de5c5ec1..0e87f3503265 100644
--- a/drivers/gpu/drm/amd/display/dc/hwss/dcn35/dcn35_init.c
+++ b/drivers/gpu/drm/amd/display/dc/hwss/dcn35/dcn35_init.c
@@ -31,6 +31,7 @@
 #include "dcn30/dcn30_hwseq.h"
 #include "dcn301/dcn301_hwseq.h"
 #include "dcn31/dcn31_hwseq.h"
+#include "dcn314/dcn314_hwseq.h"
 #include "dcn32/dcn32_hwseq.h"
 #include "dcn35/dcn35_hwseq.h"
 
@@ -158,6 +159,7 @@ static const struct hwseq_private_funcs dcn35_private_funcs = {
 	.setup_hpo_hw_control = dcn35_setup_hpo_hw_control,
 	.calculate_dccg_k1_k2_values = dcn32_calculate_dccg_k1_k2_values,
 	.set_pixels_per_cycle = dcn32_set_pixels_per_cycle,
+	.resync_fifo_dccg_dio = dcn314_resync_fifo_dccg_dio,
 	.is_dp_dig_pixel_rate_div_policy = dcn32_is_dp_dig_pixel_rate_div_policy,
 	.calculate_pix_rate_divider = dcn32_calculate_pix_rate_divider,
 	.dsc_pg_control = dcn35_dsc_pg_control,
-- 
2.37.3