BZ: 178761
In wait for vblank use usleep_range, which will use hrtimers instead of
msleep. Using msleep(1~20) there are more chances of sleeping for 20ms.
Using usleep_range uses hrtimers and hence are precise, worst case will
trigger an interrupt at the higher/max timeout.
Change-log: On replacing msleep(1) with usleep_range(1000, 2000) we have
noticed the time consumed by wait for vblank is ~4ms to ~17ms.
Change-Id: I6672e5697b01987a6d069ab06e76d97287b1f7ae
Signed-off-by: Arun R Murthy <arun.r.murthy@xxxxxxxxx>
---
drivers/gpu/drm/i915/intel_display.c | 2 +-
drivers/gpu/drm/i915/intel_dp.c | 4 ++--
drivers/gpu/drm/i915/intel_drv.h | 19 ++++++++++++-------
3 files changed, 15 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 4d4a0d9..9de2678 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -761,7 +761,7 @@ static void g4x_wait_for_vblank(struct drm_device *dev, int pipe)
frame = I915_READ(frame_reg);
- if (wait_for(I915_READ_NOTRACE(frame_reg) != frame, 50))
+ if (wait_for_us(I915_READ_NOTRACE(frame_reg) != frame, 50, 1000))
DRM_DEBUG_KMS("vblank wait timed out\n");
}
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index f1ef3d4..14927e5 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1074,7 +1074,7 @@ static void wait_panel_status(struct intel_dp *intel_dp,
I915_READ(pp_stat_reg),
I915_READ(pp_ctrl_reg));
- if (_wait_for((I915_READ(pp_stat_reg) & mask) == value, 5000, 10)) {
+ if (wait_for_ms((I915_READ(pp_stat_reg) & mask) == value, 5000, 10)) {
DRM_ERROR("Panel status timeout: status %08x control %08x\n",
I915_READ(pp_stat_reg),
I915_READ(pp_ctrl_reg));
@@ -1808,7 +1808,7 @@ void intel_edp_psr_disable(struct intel_dp *intel_dp)
I915_READ(EDP_PSR_CTL(dev)) & ~EDP_PSR_ENABLE);
/* Wait till PSR is idle */
- if (_wait_for((I915_READ(EDP_PSR_STATUS_CTL(dev)) &
+ if (wait_for_ms((I915_READ(EDP_PSR_STATUS_CTL(dev)) &
EDP_PSR_STATUS_STATE_MASK) == 0, 2000, 10))
DRM_ERROR("Timed out waiting for PSR Idle State\n");
}
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 44067bc..bbda97e 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -42,8 +42,8 @@
* having timed out, since the timeout could be due to preemption or similar and
* we've never had a chance to check the condition before the timeout.
*/
-#define _wait_for(COND, MS, W) ({ \
- unsigned long timeout__ = jiffies + msecs_to_jiffies(MS) + 1; \
+#define _wait_for(COND, TIMEOUT, MS, US) ({ \
+ unsigned long timeout__ = jiffies + msecs_to_jiffies(TIMEOUT) + 1;\
int ret__ = 0; \
while (!(COND)) { \
if (time_after(jiffies, timeout__)) { \
@@ -51,8 +51,11 @@
ret__ = -ETIMEDOUT; \
break; \
} \
- if (W && drm_can_sleep()) { \
- msleep(W); \
+ if ((MS | US) && drm_can_sleep()) { \
+ if (MS) \
+ msleep(MS); \
+ else \
+ usleep_range(US, US * 2); \
} else { \
cpu_relax(); \
} \
@@ -60,10 +63,12 @@
ret__; \
})
-#define wait_for(COND, MS) _wait_for(COND, MS, 1)
-#define wait_for_atomic(COND, MS) _wait_for(COND, MS, 0)
+#define wait_for(COND, TIMEOUT) _wait_for(COND, TIMEOUT, 1, 0)
+#define wait_for_ms(COND, TIMEOUT, MS) _wait_for(COND, TIMEOUT, MS, 0)
+#define wait_for_us(COND, TIMEOUT, US) _wait_for(COND, TIMEOUT, 0, US)
+#define wait_for_atomic(COND, TIMEOUT) _wait_for(COND, TIMEOUT, 0, 0)
#define wait_for_atomic_us(COND, US) _wait_for((COND), \
- DIV_ROUND_UP((US), 1000), 0)
+ DIV_ROUND_UP((US), 1000), 0, 0)
#define KHz(x) (1000 * (x))
#define MHz(x) KHz(1000 * (x))
--
1.7.9.5
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