[Intel-gfx] [PATCH v2 17/21] drm/i915/mtl: Update MBUS_DBOX credits

Radhakrishna Sripada
2022-08-18T23:44:32Z

Display version 14 platforms have different credits values compared to ADL-P.
Update the credits based on pipe usage.

v2: Simplify DBOX BW Credit definition(MattR)

Bspec: 49213

Cc: Jose Roberto de Souza <jose.souza@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Original Author: Caz Yokoyama
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
---
drivers/gpu/drm/i915/i915_reg.h | 4 +++
drivers/gpu/drm/i915/intel_pm.c | 47 ++++++++++++++++++++++++++++++---
2 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 5245af8d0ea8..b2b06c080d09 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1125,8 +1125,12 @@
#define MBUS_DBOX_REGULATE_B2B_TRANSACTIONS_EN REG_BIT(16) /* tgl+ */
#define MBUS_DBOX_BW_CREDIT_MASK REG_GENMASK(15, 14)
#define MBUS_DBOX_BW_CREDIT(x) REG_FIELD_PREP(MBUS_DBOX_BW_CREDIT_MASK, x)
+#define MBUS_DBOX_BW_4CREDITS_MTL REG_FIELD_PREP(MBUS_DBOX_BW_CREDIT_MASK, 0x2)
+#define MBUS_DBOX_BW_8CREDITS_MTL REG_FIELD_PREP(MBUS_DBOX_BW_CREDIT_MASK, 0x3)
#define MBUS_DBOX_B_CREDIT_MASK REG_GENMASK(12, 8)
#define MBUS_DBOX_B_CREDIT(x) REG_FIELD_PREP(MBUS_DBOX_B_CREDIT_MASK, x)
+#define MBUS_DBOX_I_CREDIT_MASK REG_GENMASK(7, 5)
+#define MBUS_DBOX_I_CREDIT(x) REG_FIELD_PREP(MBUS_DBOX_I_CREDIT_MASK, x)
#define MBUS_DBOX_A_CREDIT_MASK REG_GENMASK(3, 0)
#define MBUS_DBOX_A_CREDIT(x) REG_FIELD_PREP(MBUS_DBOX_A_CREDIT_MASK, x)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index f71b3b8b590c..5cdc2ce4f42b 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -8443,6 +8443,27 @@ void intel_dbuf_post_plane_update(struct intel_atomic_state *state)
new_dbuf_state->enabled_slices);
}

+static bool xelpdp_is_one_pipe_per_dbuf_bank(enum pipe pipe, u8 active_pipes)
+{
+ switch (pipe) {
+ case PIPE_A:
+ case PIPE_D:
+ if (is_power_of_2(active_pipes & (BIT(PIPE_A) | BIT(PIPE_D))))
+ return true;
+ break;
+ case PIPE_B:
+ case PIPE_C:
+ if (is_power_of_2(active_pipes & (BIT(PIPE_B) | BIT(PIPE_C))))
+ return true;
+ break;
+ default: /* to suppress compiler warning */
+ MISSING_CASE(pipe);
+ break;
+ }
+
+ return false;
+}
+
void intel_mbus_dbox_update(struct intel_atomic_state *state)
{
struct drm_i915_private *i915 = to_i915(state->base.dev);
@@ -8462,20 +8483,28 @@ void intel_mbus_dbox_update(struct intel_atomic_state *state)
new_dbuf_state->active_pipes == old_dbuf_state->active_pipes))
return;

+ if (DISPLAY_VER(i915) >= 14)
+ val |= MBUS_DBOX_I_CREDIT(2);
+
if (DISPLAY_VER(i915) >= 12) {
val |= MBUS_DBOX_B2B_TRANSACTIONS_MAX(16);
val |= MBUS_DBOX_B2B_TRANSACTIONS_DELAY(1);
val |= MBUS_DBOX_REGULATE_B2B_TRANSACTIONS_EN;
}

- /* Wa_22010947358:adl-p */
- if (IS_ALDERLAKE_P(i915))
+ if (DISPLAY_VER(i915) >= 14)
+ val |= new_dbuf_state->joined_mbus ? MBUS_DBOX_A_CREDIT(12) :
+ MBUS_DBOX_A_CREDIT(8);
+ else if (IS_ALDERLAKE_P(i915))
+ /* Wa_22010947358:adl-p */
val |= new_dbuf_state->joined_mbus ? MBUS_DBOX_A_CREDIT(6) :
MBUS_DBOX_A_CREDIT(4);
else
val |= MBUS_DBOX_A_CREDIT(2);

- if (IS_ALDERLAKE_P(i915)) {
+ if (DISPLAY_VER(i915) >= 14) {
+ val |= MBUS_DBOX_B_CREDIT(0xA);
+ } else if (IS_ALDERLAKE_P(i915)) {
val |= MBUS_DBOX_BW_CREDIT(2);
val |= MBUS_DBOX_B_CREDIT(8);
} else if (DISPLAY_VER(i915) >= 12) {
@@ -8487,10 +8516,20 @@ void intel_mbus_dbox_update(struct intel_atomic_state *state)
}

for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) {
+ u32 pipe_val = val;
+
if (!new_crtc_state->hw.active ||
!intel_crtc_needs_modeset(new_crtc_state))
continue;

- intel_de_write(i915, PIPE_MBUS_DBOX_CTL(crtc->pipe), val);
+ if (DISPLAY_VER(i915) >= 14) {
+ if (xelpdp_is_one_pipe_per_dbuf_bank(crtc->pipe,
+ new_dbuf_state->active_pipes))
+ pipe_val |= MBUS_DBOX_BW_8CREDITS_MTL;
+ else
+ pipe_val |= MBUS_DBOX_BW_4CREDITS_MTL;
+ }
+
+ intel_de_write(i915, PIPE_MBUS_DBOX_CTL(crtc->pipe), pipe_val);
}
}
--
2.25.1