Hi,
On Monday 31 October 2016 11:33 PM, Paulo Zanoni wrote:
Em Qui, 2016-10-13 às 16:28 +0530, Kumar, Mahesh escreveu:
This patch make changes to use linetime latency instead of allocated
DDB size during plane watermark calculation in switch case, This is
required to implement new DDB allocation algorithm.
In New Algorithm DDB is allocated based on WM values, because of
which
number of DDB blocks will not be available during WM calculation,
So this "linetime latency" is suggested by SV/HW team to use during
switch-case for WM blocks selection.
Changes since v1:
- Rebase on top of Paulo's patch series
Changes since v2:
- Fix if-else condition (pointed by Maarten)
Signed-off-by: "Kumar, Mahesh" <mahesh1.kumar@xxxxxxxxx>
---
drivers/gpu/drm/i915/intel_pm.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/intel_pm.c
b/drivers/gpu/drm/i915/intel_pm.c
index 7f1748a..098336d 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3616,10 +3616,14 @@ static int skl_compute_plane_wm(const struct
drm_i915_private *dev_priv,
fb->modifier[0] == I915_FORMAT_MOD_Yf_TILED) {
selected_result = max(method2, y_tile_minimum);
} else {
+ uint32_t linetime_us = 0;
+
+ linetime_us = DIV_ROUND_UP(width * 1000,
+ skl_pipe_pixel_rate(cstate));
Can't we just call skl_compute_linetime_wm() here? I don't like having
two pieces of the code computing the same thing. My last round of bug
fixes included a fix for duplicated code that got out of sync after
spec changes.
These two have different values in skl_compute_linetime_wm we multiply
by 8, not here.
if ((cpp * cstate->base.adjusted_mode.crtc_htotal /
512 < 1) &&
(plane_bytes_per_line / 512 < 1))
selected_result = method2;
- else if ((ddb_allocation / plane_blocks_per_line) >=
1)
+ else if (latency >= linetime_us)
Still doesn't match the spec. The "ddb_allocation /
planes_block_per_line" is still necessary.
After New algorithm patch, we will not have access to ddb_allocation, as
allocation will happen later.
So we can't use ddb_allocation in our calculation, This check in Bspec
is kept for the environment/OS where we don't allocate DDB dynamically.
hence those OS will have access to ddb_allocation during WM calculation
phase.
thanks,
Regards,
-Mahesh
selected_result = min(method1, method2);
else
selected_result = method1;
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