# \[PATCH 1/2\] mmc: Use mmc\_delay() instead of mdelay() for time delay

- From: Chunhe Lan \<hidden\>
- Date: 2011-08-25 09:56:00 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2011/08/9466080
- Thread: https://ratatoskr.run/linux-mmc/2011/08/9466080/t.md

```text
The mmc_delay() is a wrapper function for mdelay() and msleep().

    o mdelay() -- block the system when busy-waiting.
    o msleep() -- suspend the currently running task to enable CPU
                  to process other tasks, so it is non-blocking
                  regarding the whole system.

When the desired delay time is more than a period of timer interrupt,
just use msleep(). Change mdelay() to mmc_delay() to avoid chewing
CPU when busy wait.

Signed-off-by: Shengzhou Liu <redacted>
Signed-off-by: Chunhe Lan <redacted>
Cc: Chris Ball <redacted>
---
 drivers/mmc/host/sdhci-esdhc.h |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci-esdhc.h
index c3b08f1..42b1d9eb 100644
--- a/drivers/mmc/host/sdhci-esdhc.h
+++ b/drivers/mmc/host/sdhci-esdhc.h
@@ -1,7 +1,7 @@
 /*
  * Freescale eSDHC controller driver generics for OF and pltfm.
  *
- * Copyright (c) 2007 Freescale Semiconductor, Inc.
+ * Copyright (c) 2007, 2011 Freescale Semiconductor, Inc.
  * Copyright (c) 2009 MontaVista Software, Inc.
  * Copyright (c) 2010 Pengutronix e.K.
  *   Author: Wolfram Sang <w.sang@pengutronix.de>
@@ -14,6 +14,8 @@
 #ifndef _DRIVERS_MMC_SDHCI_ESDHC_H
 #define _DRIVERS_MMC_SDHCI_ESDHC_H
 
+#include "../core/core.h"
+
 /*
  * Ops and quirks for the Freescale eSDHC controller.
  */
@@ -73,7 +75,7 @@ static inline void esdhc_set_clock(struct sdhci_host *host, unsigned int clock)
 		| (div << ESDHC_DIVIDER_SHIFT)
 		| (pre_div << ESDHC_PREDIV_SHIFT));
 	sdhci_writel(host, temp, ESDHC_SYSTEM_CONTROL);
-	mdelay(100);
+	mmc_delay(100);
 out:
 	host->clock = clock;
 }
-- 
1.7.5.1
```