From: Ryan QIAN Date: Mon, 8 Oct 2012 23:44:34 +0000 (+0800) Subject: ENGR00227420 mmc: sdhci: shorten the delay on disabling clk X-Git-Tag: v3.0.35-fsl~373 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=7bc9d69b0b8d3d9ebd425d76769c4f752724473e;p=karo-tx-linux.git ENGR00227420 mmc: sdhci: shorten the delay on disabling clk - change the delay from 10 * HZ to 1 * HZ, though (1 * HZ) might not be the best, just as a base. 1. Since the request has been moved out of interrupt context, there will be no more calling enable_clk in interrupt context. So it's not necessary to keep such a long delay on disabling clock in order to save power. 2. Still keeping the 1*HZ of delay is to avoid frequently enabling/disabling clock. eMMC card performance test result with bonnie++: (512M RAM, 1GB data, 1K buffer) ------------------------------------------------------------------------------ | | 1*HZ | 10 * HZ | ------------------------------------------------------------------------------ | Read | ~24.1MB/s | ~23.9MB/s | ------------------------------------------------------------------------------ | Write | ~10.5MB/s | ~10.5MB/s | ------------------------------------------------------------------------------ WiFi card performance test result with iperf is quite same: ~21Mbps (AR6003@2.4G, TCP, TCP window size option 1MB both for server and client) Acked-by: Robby CAI Signed-off-by: Ryan QIAN --- diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 49bbaa52f7e6..e8f78aebdefe 100755 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -30,7 +30,7 @@ #include "sdhci.h" #define DRIVER_NAME "sdhci" -#define CLK_TIMEOUT (10 * HZ) +#define CLK_TIMEOUT (1 * HZ) #define DBG(f, x...) \ pr_debug(DRIVER_NAME " [%s()]: " f, __func__,## x)