[PATCH v3 2/2] mmc: Use mmc_delay() instead of mdelay() for time delay

* [PATCH v3 2/2] mmc: Use mmc_delay() instead of mdelay() for time delay
@ 2012-08-10 22:26 ` Chunhe Lan
  0 siblings, 0 replies; 2+ messages in thread
From: Chunhe Lan @ 2012-08-10 22:26 UTC (permalink / raw)
  To: linux-mmc; +Cc: Shengzhou Liu, kumar.gala, cjb, linuxppc-dev, Chunhe Lan

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 <b36685@freescale.com>
Signed-off-by: Chunhe Lan <Chunhe.Lan@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Cc: Chris Ball <cjb@laptop.org>
---
 drivers/mmc/host/sdhci-esdhc.h |    4 ++--
 drivers/mmc/host/sdhci.c       |   10 +++++-----
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci-esdhc.h
index b97b2f5..272cea0 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, 2012 Freescale Semiconductor, Inc.
  * Copyright (c) 2009 MontaVista Software, Inc.
  * Copyright (c) 2010 Pengutronix e.K.
  *   Author: Wolfram Sang <w.sang@pengutronix.de>
@@ -73,7 +73,7 @@ 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(1);
+	mmc_delay(1);
 out:
 	host->clock = clock;
 }
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 9a11dc3..6e67bc4 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -205,7 +205,7 @@ static void sdhci_reset(struct sdhci_host *host, u8 mask)
 			return;
 		}
 		timeout--;
-		mdelay(1);
+		mmc_delay(1);
 	}
 
 	if (host->ops->platform_reset_exit)
@@ -997,7 +997,7 @@ static void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
 			return;
 		}
 		timeout--;
-		mdelay(1);
+		mmc_delay(1);
 	}
 
 	mod_timer(&host->timer, jiffies + 10 * HZ);
@@ -1178,7 +1178,7 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
 			return;
 		}
 		timeout--;
-		mdelay(1);
+		mmc_delay(1);
 	}
 
 	clk |= SDHCI_CLOCK_CARD_EN;
@@ -1243,7 +1243,7 @@ static int sdhci_set_power(struct sdhci_host *host, unsigned short power)
 	 * can apply clock after applying power
 	 */
 	if (host->quirks & SDHCI_QUIRK_DELAY_AFTER_POWER)
-		mdelay(10);
+		mmc_delay(10);
 
 	return power;
 }
@@ -1850,7 +1850,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 		ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
 		tuning_loop_counter--;
 		timeout--;
-		mdelay(1);
+		mmc_delay(1);
 	} while (ctrl & SDHCI_CTRL_EXEC_TUNING);
 
 	/*
-- 
1.7.6.5

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