[PATCH v3] drm/i915/display: Don't update DBUF_TRACKER_STATE_SERVICE

[Ravi Kumar Vodapalli]

The bspec only asks the driver to reprogram the DBUF_CTL's
DBUF_TRACKER_STATE_SERVICE field to 0x8 on DG2 and platforms with
display version 12. All other platforms should avoid reprogramming
this register at driver init.

Although we've been accidentally reprogramming DBUF_CTL on platforms
where the spec does not ask us to, that mistake has been harmless so
far because the value being programmed by the driver happened to
match the hardware's default settings.

So, update DBUF_TRACKER_STATE_SERVICE field to 0x8 only for
1. display version 12
2. DG2.
Other platforms unless stated should use their default value.

Bspec: 49213
Signed-off-by: Ravi Kumar Vodapalli <ravi.kumar.vodapalli at intel.com>
---
 drivers/gpu/drm/i915/display/intel_display_power.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c
index 34465d56def0..9c20459053fe 100644
--- a/drivers/gpu/drm/i915/display/intel_display_power.c
+++ b/drivers/gpu/drm/i915/display/intel_display_power.c
@@ -1126,9 +1126,6 @@ static void gen12_dbuf_slices_config(struct intel_display *display)
 {
 	enum dbuf_slice slice;
 
-	if (display->platform.alderlake_p)
-		return;
-
 	for_each_dbuf_slice(display, slice)
 		intel_de_rmw(display, DBUF_CTL_S(slice),
 			     DBUF_TRACKER_STATE_SERVICE_MASK,
@@ -1681,7 +1678,7 @@ static void icl_display_core_init(struct intel_display *display,
 	/* 4. Enable CDCLK. */
 	intel_cdclk_init_hw(display);
 
-	if (DISPLAY_VER(display) >= 12)
+	if (DISPLAY_VER(display) == 12 || display->platform.dg2)
 		gen12_dbuf_slices_config(display);
 
 	/* 5. Enable DBUF. */
-- 
2.25.1