From: Caz Yokoyama <caz.yokoyama@xxxxxxxxx>
Do not overwrite registers that don't need to change from default
value to 0.
bspec 49213
Cc: Radhakrishna Sripada <radhakrishna.sripada@xxxxxxxxx>
Cc: José Roberto de Souza <jose.souza@xxxxxxxxx>
Cc: Matt Roper <matthew.d.roper@xxxxxxxxx>
Signed-off-by: Caz Yokoyama <caz.yokoyama@xxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_display.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index a7ca38613f89..9190a3bc28a8 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -2955,18 +2955,23 @@ static void icl_pipe_mbus_enable(struct intel_crtc *crtc, bool joined_mbus)
{
struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
enum pipe pipe = crtc->pipe;
- u32 val;
+ u32 val = intel_de_read(dev_priv, PIPE_MBUS_DBOX_CTL(pipe));
+ val &= ~MBUS_DBOX_A_CREDIT_MASK;
/* Wa_22010947358:adl-p */
if (IS_ALDERLAKE_P(dev_priv))
- val = joined_mbus ? MBUS_DBOX_A_CREDIT(6) : MBUS_DBOX_A_CREDIT(4);
+ val |= joined_mbus ? MBUS_DBOX_A_CREDIT(6) : MBUS_DBOX_A_CREDIT(4);
else
- val = MBUS_DBOX_A_CREDIT(2);
+ val |= MBUS_DBOX_A_CREDIT(2);
- if (DISPLAY_VER(dev_priv) >= 12) {
+ if (IS_ALDERLAKE_P(dev_priv)) {
+ /* Take effect hardware default MBUS_DBOX_B_CREDIT(8) */
+ } else if (DISPLAY_VER(dev_priv) >= 12) {
+ val &= ~(MBUS_DBOX_BW_CREDIT_MASK | MBUS_DBOX_B_CREDIT_MASK);
val |= MBUS_DBOX_BW_CREDIT(2);
val |= MBUS_DBOX_B_CREDIT(12);
} else {
+ val &= ~(MBUS_DBOX_BW_CREDIT_MASK | MBUS_DBOX_B_CREDIT_MASK);
val |= MBUS_DBOX_BW_CREDIT(1);
val |= MBUS_DBOX_B_CREDIT(8);
}
--
2.31.1.362.g311531c9de
