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* [PATCH] mmc: core: Use usleep_range for delays less than 20ms
@ 2011-11-09  3:49 Sujit Reddy Thumma
  0 siblings, 0 replies; only message in thread
From: Sujit Reddy Thumma @ 2011-11-09  3:49 UTC (permalink / raw)
  To: linux-mmc; +Cc: Sujit Reddy Thumma, linux-arm-msm, cjb

msleep of any delay less than 20ms (or 2 jiffies) would
give an unpredictable delay (most of the times as ~20ms).
Use usleep_range in mmc_delay() for delays less than two jiffies.

Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
---
 drivers/mmc/core/core.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
index 14664f1..45a6a12 100644
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -50,6 +50,8 @@ static inline void mmc_delay(unsigned int ms)
 	if (ms < 1000 / HZ) {
 		cond_resched();
 		mdelay(ms);
+	} else if (ms < jiffies_to_msecs(2)) {
+		usleep_range(ms * 1000, (ms + 1) * 1000);
 	} else {
 		msleep(ms);
 	}
-- 
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

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2011-11-09  3:49 [PATCH] mmc: core: Use usleep_range for delays less than 20ms Sujit Reddy Thumma

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