drm/i915/icl: Enable 2nd DBuf slice only when needed
ICL has two slices of DBuf, each slice of size 1024 blocks.
We should not always enable slice-2. It should be enabled only if
display total required BW is > 12GBps OR more than 1 pipes are enabled.
Changes since V1:
- typecast total_data_rate to u64 before multiplication to solve any
possible overflow (Rodrigo)
- fix where skl_wm_get_hw_state was memsetting ddb, resulting
enabled_slices to become zero
- Fix the logic of calculating ddb_size
Changes since V2:
- If no-crtc is part of commit required_slices will have value "0",
don't try to disable DBuf slice.
Changes since V3:
- Create a generic helper to enable/disable slice
- don't return early if total_data_rate is 0, it may be cursor only
commit, or atomic modeset without any plane.
Changes since V4:
- Solve checkpatch warnings
- use kernel types u8/u64 instead of uint8_t/uint64_t
Changes since V5:
- Rebase
Signed-off-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180426142517.16643-3-mahesh1.kumar@intel.com
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index a29e6d5..3e72e9e 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3771,9 +3771,42 @@ bool intel_can_enable_sagv(struct drm_atomic_state *state)
return true;
}
+static unsigned int intel_get_ddb_size(struct drm_i915_private *dev_priv,
+ const struct intel_crtc_state *cstate,
+ const unsigned int total_data_rate,
+ const int num_active,
+ struct skl_ddb_allocation *ddb)
+{
+ const struct drm_display_mode *adjusted_mode;
+ u64 total_data_bw;
+ u16 ddb_size = INTEL_INFO(dev_priv)->ddb_size;
+
+ WARN_ON(ddb_size == 0);
+
+ if (INTEL_GEN(dev_priv) < 11)
+ return ddb_size - 4; /* 4 blocks for bypass path allocation */
+
+ adjusted_mode = &cstate->base.adjusted_mode;
+ total_data_bw = (u64)total_data_rate * drm_mode_vrefresh(adjusted_mode);
+
+ /*
+ * 12GB/s is maximum BW supported by single DBuf slice.
+ */
+ if (total_data_bw >= GBps(12) || num_active > 1) {
+ ddb->enabled_slices = 2;
+ } else {
+ ddb->enabled_slices = 1;
+ ddb_size /= 2;
+ }
+
+ return ddb_size;
+}
+
static void
skl_ddb_get_pipe_allocation_limits(struct drm_device *dev,
const struct intel_crtc_state *cstate,
+ const unsigned int total_data_rate,
+ struct skl_ddb_allocation *ddb,
struct skl_ddb_entry *alloc, /* out */
int *num_active /* out */)
{
@@ -3796,11 +3829,8 @@ skl_ddb_get_pipe_allocation_limits(struct drm_device *dev,
else
*num_active = hweight32(dev_priv->active_crtcs);
- ddb_size = INTEL_INFO(dev_priv)->ddb_size;
- WARN_ON(ddb_size == 0);
-
- if (INTEL_GEN(dev_priv) < 11)
- ddb_size -= 4; /* 4 blocks for bypass path allocation */
+ ddb_size = intel_get_ddb_size(dev_priv, cstate, total_data_rate,
+ *num_active, ddb);
/*
* If the state doesn't change the active CRTC's, then there's
@@ -4261,7 +4291,11 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
return 0;
}
- skl_ddb_get_pipe_allocation_limits(dev, cstate, alloc, &num_active);
+ total_data_rate = skl_get_total_relative_data_rate(cstate,
+ plane_data_rate,
+ uv_plane_data_rate);
+ skl_ddb_get_pipe_allocation_limits(dev, cstate, total_data_rate, ddb,
+ alloc, &num_active);
alloc_size = skl_ddb_entry_size(alloc);
if (alloc_size == 0)
return 0;
@@ -4296,9 +4330,6 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
*
* FIXME: we may not allocate every single block here.
*/
- total_data_rate = skl_get_total_relative_data_rate(cstate,
- plane_data_rate,
- uv_plane_data_rate);
if (total_data_rate == 0)
return 0;
@@ -5492,8 +5523,12 @@ void skl_wm_get_hw_state(struct drm_device *dev)
/* Fully recompute DDB on first atomic commit */
dev_priv->wm.distrust_bios_wm = true;
} else {
- /* Easy/common case; just sanitize DDB now if everything off */
- memset(ddb, 0, sizeof(*ddb));
+ /*
+ * Easy/common case; just sanitize DDB now if everything off
+ * Keep dbuf slice info intact
+ */
+ memset(ddb->plane, 0, sizeof(ddb->plane));
+ memset(ddb->uv_plane, 0, sizeof(ddb->uv_plane));
}
}