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

Kyungmin Park kmpark at infradead.org
Thu Aug 25 20:23:35 EST 2011


On Thu, Aug 25, 2011 at 5:54 PM, Chunhe Lan <Chunhe.Lan at freescale.com> wrote:
> 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 at freescale.com>
> Signed-off-by: Chunhe Lan <Chunhe.Lan at freescale.com>
> Cc: Chris Ball <cjb at laptop.org>
> ---
>  drivers/mmc/host/sdhci.c |   11 ++++++-----
>  1 files changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 0e02cc1..0cb5dc1 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -27,6 +27,7 @@
>  #include <linux/mmc/host.h>
>
>  #include "sdhci.h"
> +#include "../core/core.h"

Doesn't better to move the mmc_delay() to "include/linux/mmc/core.h"?
and include it.
I think It's not proper include syntax using relative path.

Thank you,
Kyungmin Park
>
>  #define DRIVER_NAME "sdhci"
>
> @@ -186,7 +187,7 @@ static void sdhci_reset(struct sdhci_host *host, u8 mask)
>                        return;
>                }
>                timeout--;
> -               mdelay(1);
> +               mmc_delay(1);
>        }
>
>        if (host->ops->platform_reset_exit)
> @@ -957,7 +958,7 @@ 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);
> @@ -1127,7 +1128,7 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
>                        return;
>                }
>                timeout--;
> -               mdelay(1);
> +               mmc_delay(1);
>        }
>
>        clk |= SDHCI_CLOCK_CARD_EN;
> @@ -1192,7 +1193,7 @@ static void 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);
>  }
>
>  /*****************************************************************************\
> @@ -1712,7 +1713,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc)
>                ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>                tuning_loop_counter--;
>                timeout--;
> -               mdelay(1);
> +               mmc_delay(1);
>        } while (ctrl & SDHCI_CTRL_EXEC_TUNING);
>
>        /*
> --
> 1.7.5.1
>
>
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