From: Ivan Lipski <[email protected]>
[WHY]
On DCN21, dccg2_init() is called in dcn10_init_hw() before
bios_golden_init(). During S0i3 resume, BIOS sets MICROSECOND_TIME_BASE_DIV
to 0x00120464 as a marker. dccg2_init() overwrites this to 0x00120264,
causing dcn21_s0i3_golden_init_wa() to misdetect the state and skip golden
init.
Eventually during the resume sequence, a flip timeout occurs.
[HOW]
Skip DCCG on dccg2_is_s0i3_golden_init_wa_done() on DCN21.
Fixes: f5472343f468 ("drm/amd/display: Migrate DCCG registers access from hwseq
to dccg component.")
Reviewed-by: Aurabindo Pillai <[email protected]>
Signed-off-by: Ivan Lipski <[email protected]>
Signed-off-by: Alex Hung <[email protected]>
---
.../amd/display/dc/dccg/dcn21/dcn21_dccg.c | 21 ++++++++++++++++++-
1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dccg/dcn21/dcn21_dccg.c
b/drivers/gpu/drm/amd/display/dc/dccg/dcn21/dcn21_dccg.c
index b48dcafbae66..bdc3ce5d4f47 100644
--- a/drivers/gpu/drm/amd/display/dc/dccg/dcn21/dcn21_dccg.c
+++ b/drivers/gpu/drm/amd/display/dc/dccg/dcn21/dcn21_dccg.c
@@ -96,6 +96,25 @@ static void dccg21_update_dpp_dto(struct dccg *dccg, int
dpp_inst, int req_dppcl
dccg->pipe_dppclk_khz[dpp_inst] = req_dppclk;
}
+/*
+ * On DCN21 S0i3 resume, BIOS programs MICROSECOND_TIME_BASE_DIV to
+ * 0x00120464 as a marker that golden init has already been done.
+ * dcn21_s0i3_golden_init_wa() reads this marker later in bios_golden_init()
+ * to decide whether to skip golden init.
+ *
+ * dccg2_init() unconditionally overwrites MICROSECOND_TIME_BASE_DIV to
+ * 0x00120264, destroying the marker before it can be read.
+ *
+ * Guard the call: if the S0i3 marker is present, skip dccg2_init() so the
+ * WA can function correctly. bios_golden_init() will handle init in that case.
+ */
+static void dccg21_init(struct dccg *dccg)
+{
+ if (dccg2_is_s0i3_golden_init_wa_done(dccg))
+ return;
+
+ dccg2_init(dccg);
+}
static const struct dccg_funcs dccg21_funcs = {
.update_dpp_dto = dccg21_update_dpp_dto,
@@ -103,7 +122,7 @@ static const struct dccg_funcs dccg21_funcs = {
.set_fifo_errdet_ovr_en = dccg2_set_fifo_errdet_ovr_en,
.otg_add_pixel = dccg2_otg_add_pixel,
.otg_drop_pixel = dccg2_otg_drop_pixel,
- .dccg_init = dccg2_init,
+ .dccg_init = dccg21_init,
.refclk_setup = dccg2_refclk_setup, /* Deprecated - for backward
compatibility only */
.allow_clock_gating = dccg2_allow_clock_gating,
.enable_memory_low_power = dccg2_enable_memory_low_power,
--
2.43.0
