sdhci_set_clock or sdhci_reset or sdhci_send_command may be used in
critical region which is protected by spin_lock_irqsave. Thus, these
functions will delay the responsing of the kernel interrupts.
So in this case, using a mdelay will cause unnecessary latency. Our
hardware, in most case will not cause 1ms to finish its job. Using
udelay instead can reduce it.
By default, sdhci_do_set_ios will need about 1ms to finish in my platform.
After using udelay instead, sdhci_do_set_ios only need a few microseconds.
Signed-off-by: Shawn.Dong <shawn.dong...@gmail.com>
---
drivers/mmc/host/sdhci.c | 12 ++++++------
1 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 6d8eea3..9314cd1 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -195,7 +195,7 @@ static void sdhci_reset(struct sdhci_host *host, u8 mask)
host->clock = 0;
/* Wait max 100 ms */
- timeout = 100;
+ timeout = 10000;
/* hw clears the bit when it's done */
while (sdhci_readb(host, SDHCI_SOFTWARE_RESET) & mask) {
@@ -206,7 +206,7 @@ static void sdhci_reset(struct sdhci_host *host, u8 mask)
return;
}
timeout--;
- mdelay(1);
+ udelay(10);
}
if (host->ops->platform_reset_exit)
@@ -959,7 +959,7 @@ static void sdhci_send_command(struct sdhci_host *host,
struct mmc_command *cmd)
WARN_ON(host->cmd);
/* Wait max 10 ms */
- timeout = 10;
+ timeout = 1000;
mask = SDHCI_CMD_INHIBIT;
if ((cmd->data != NULL) || (cmd->flags & MMC_RSP_BUSY))
@@ -980,7 +980,7 @@ static void sdhci_send_command(struct sdhci_host *host,
struct mmc_command *cmd)
return;
}
timeout--;
- mdelay(1);
+ udelay(10);
}
mod_timer(&host->timer, jiffies + 10 * HZ);
@@ -1140,7 +1140,7 @@ static void sdhci_set_clock(struct sdhci_host *host,
unsigned int clock)
sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
/* Wait max 20 ms */
- timeout = 20;
+ timeout = 2000;
while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
& SDHCI_CLOCK_INT_STABLE)) {
if (timeout == 0) {
@@ -1150,7 +1150,7 @@ static void sdhci_set_clock(struct sdhci_host *host,
unsigned int clock)
return;
}
timeout--;
- mdelay(1);
+ udelay(10);
}
clk |= SDHCI_CLOCK_CARD_EN;
--
1.7.3.4
--
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