mmc: sdhci-of-esdhc: poll ESDHC_CLOCK_STABLE bit with udelay

The loop to poll ESDHC_CLOCK_STABLE bit with mdelay would waste time
because the time to stabilize is much less than 1 ms. This patch is
to use udelay instead to avoid time wasting.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index 7518360c03d23b2046402b1c96152ea70fca32f2..77dfc5915ddce5523f21512d9bc03834b3bbf2a8 100644 (file)
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -445,7 +445,7 @@ static void esdhc_of_set_clock(struct sdhci_host *host, unsigned int clock)
        struct sdhci_esdhc *esdhc = sdhci_pltfm_priv(pltfm_host);
        int pre_div = 1;
        int div = 1;
-       u32 timeout;
+       ktime_t timeout;
        u32 temp;
 
        host->mmc->actual_clock = 0;
@@ -489,15 +489,14 @@ static void esdhc_of_set_clock(struct sdhci_host *host, unsigned int clock)
        sdhci_writel(host, temp, ESDHC_SYSTEM_CONTROL);
 
        /* Wait max 20 ms */
-       timeout = 20;
+       timeout = ktime_add_ms(ktime_get(), 20);
        while (!(sdhci_readl(host, ESDHC_PRSSTAT) & ESDHC_CLOCK_STABLE)) {
-               if (timeout == 0) {
+               if (ktime_after(ktime_get(), timeout)) {
                        pr_err("%s: Internal clock never stabilised.\n",
                                mmc_hostname(host->mmc));
                        return;
                }
-               timeout--;
-               mdelay(1);
+               udelay(10);
        }
 
        temp |= ESDHC_CLOCK_SDCLKEN;