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authorAdrian Hunter <adrian.hunter@intel.com>2017-03-20 19:50:31 +0200
committerUlf Hansson <ulf.hansson@linaro.org>2017-04-24 21:41:26 +0200
commit5a436cc0af6202265de0d2d2d35f1b4fd85caf3b (patch)
tree401f9c7f6f131b1239d249f6e1a25b4b53cc2b3e /drivers/mmc/host/sdhci.c
parent660fc733bd7436f4fa1a351376493e635514ed64 (diff)
mmc: sdhci: Optimize delay loops
The delay loops for reset and clock enable always take at least 1 ms because they use mdelay(1). However they can take a lot less time e.g. less than 50us. Use ktime and reduce the delay to 10 microseconds per loop. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Diffstat (limited to 'drivers/mmc/host/sdhci.c')
-rw-r--r--drivers/mmc/host/sdhci.c19
1 files changed, 9 insertions, 10 deletions
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 63bc33a54d0d..777c82efce1d 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -14,6 +14,7 @@
*/
#include <linux/delay.h>
+#include <linux/ktime.h>
#include <linux/highmem.h>
#include <linux/io.h>
#include <linux/module.h>
@@ -165,7 +166,7 @@ static void sdhci_runtime_pm_bus_off(struct sdhci_host *host)
void sdhci_reset(struct sdhci_host *host, u8 mask)
{
- unsigned long timeout;
+ ktime_t timeout;
sdhci_writeb(host, mask, SDHCI_SOFTWARE_RESET);
@@ -177,18 +178,17 @@ void sdhci_reset(struct sdhci_host *host, u8 mask)
}
/* Wait max 100 ms */
- timeout = 100;
+ timeout = ktime_add_ms(ktime_get(), 100);
/* hw clears the bit when it's done */
while (sdhci_readb(host, SDHCI_SOFTWARE_RESET) & mask) {
- if (timeout == 0) {
+ if (ktime_after(ktime_get(), timeout)) {
pr_err("%s: Reset 0x%x never completed.\n",
mmc_hostname(host->mmc), (int)mask);
sdhci_dumpregs(host);
return;
}
- timeout--;
- mdelay(1);
+ udelay(10);
}
}
EXPORT_SYMBOL_GPL(sdhci_reset);
@@ -1346,24 +1346,23 @@ EXPORT_SYMBOL_GPL(sdhci_calc_clk);
void sdhci_enable_clk(struct sdhci_host *host, u16 clk)
{
- unsigned long timeout;
+ ktime_t timeout;
clk |= SDHCI_CLOCK_INT_EN;
sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
/* Wait max 20 ms */
- timeout = 20;
+ timeout = ktime_add_ms(ktime_get(), 20);
while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
& SDHCI_CLOCK_INT_STABLE)) {
- if (timeout == 0) {
+ if (ktime_after(ktime_get(), timeout)) {
pr_err("%s: Internal clock never stabilised.\n",
mmc_hostname(host->mmc));
sdhci_dumpregs(host);
return;
}
- timeout--;
spin_unlock_irq(&host->lock);
- usleep_range(900, 1100);
+ udelay(10);
spin_lock_irq(&host->lock);
}