After applying wait-boost we often find ourselves stuck at higher clocks
than required. The current threshold value requires the GPU to be
continuously and completely idle for 313ms before it is dropped by one
bin. Conversely, we require the GPU to be busy for an average of 90% over
a 84ms before we upclock. So the current thresholds almost never
downclock the GPU, and respond very slowly to sudden demands for more
power.
A more sensible approach, as discussed in the bspec, is to a continuous
threshold for upclocking, and an average value for downclocking.
RFM - request for measurement!
Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk>
Cc: Kenneth Graunke <kenn...@whitecape.org>
Cc: Stéphane Marchesin <stephane.marche...@gmail.com>
Cc: "Meng, Mengmeng" <mengmeng.m...@intel.com>
Cc: "Zhuang, Lena" <lena.zhu...@intel.com>
---
drivers/gpu/drm/i915/i915_reg.h | 2 +-
drivers/gpu/drm/i915/intel_pm.c | 15 +++++++++------
2 files changed, 10 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 3f5bddd..04b23cb 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -4620,7 +4620,7 @@
#define GEN6_RP_UP_IDLE_MIN (0x1<<3)
#define GEN6_RP_UP_BUSY_AVG (0x2<<3)
#define GEN6_RP_UP_BUSY_CONT (0x4<<3)
-#define GEN7_RP_DOWN_IDLE_AVG (0x2<<0)
+#define GEN6_RP_DOWN_IDLE_AVG (0x2<<0)
#define GEN6_RP_DOWN_IDLE_CONT (0x1<<0)
#define GEN6_RP_UP_THRESHOLD 0xA02C
#define GEN6_RP_DOWN_THRESHOLD 0xA030
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index aa98b0b..1dcda84 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3581,10 +3581,13 @@ static void gen6_enable_rps(struct drm_device *dev)
dev_priv->rps.max_delay << 24 |
dev_priv->rps.min_delay << 16);
- I915_WRITE(GEN6_RP_UP_THRESHOLD, 59400);
- I915_WRITE(GEN6_RP_DOWN_THRESHOLD, 245000);
- I915_WRITE(GEN6_RP_UP_EI, 66000);
- I915_WRITE(GEN6_RP_DOWN_EI, 350000);
+ /* Upclock if continuously busy for 5ms, ~1/3 of a frame */
+ I915_WRITE(GEN6_RP_UP_EI, 16000); /* not used for continuous mode */
+ I915_WRITE(GEN6_RP_UP_THRESHOLD, 5000);
+
+ /* Downclock if less than 66% busy over 33ms, last ~2 frames */
+ I915_WRITE(GEN6_RP_DOWN_EI, 33000);
+ I915_WRITE(GEN6_RP_DOWN_THRESHOLD, 22000);
I915_WRITE(GEN6_RP_IDLE_HYSTERSIS, 10);
I915_WRITE(GEN6_RP_CONTROL,
@@ -3592,8 +3595,8 @@ static void gen6_enable_rps(struct drm_device *dev)
GEN6_RP_MEDIA_HW_NORMAL_MODE |
GEN6_RP_MEDIA_IS_GFX |
GEN6_RP_ENABLE |
- GEN6_RP_UP_BUSY_AVG |
- (IS_HASWELL(dev) ? GEN7_RP_DOWN_IDLE_AVG :
GEN6_RP_DOWN_IDLE_CONT));
+ GEN6_RP_UP_BUSY_CONT |
+ GEN6_RP_DOWN_IDLE_AVG);
ret = sandybridge_pcode_write(dev_priv,
GEN6_PCODE_WRITE_MIN_FREQ_TABLE, 0);
if (!ret) {
--
1.8.4.rc3
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx
