From 9d7c6eee523c78b6ea4b56bd3927860d850616e5 Mon Sep 17 00:00:00 2001 From: Jarkko Lavinen Date: Wed, 26 Mar 2008 16:10:02 -0400 Subject: [PATCH] MMC: OMAP: Do not busy wait for end of command for ever The limit was a fixed 100k limit in the busy loop, which is not accurate. It would better to have time limit for the worst case which occurs when sending 80 cycles at 400 kHz and takes about 200 microseconds, so limit the max time spend in the busy loop for some 250 microseconds. Signed-off-by: Jarkko Lavinen Signed-off-by: Pierre Ossman --- drivers/mmc/host/omap.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/omap.c b/drivers/mmc/host/omap.c index ab0974d..14759e9 100644 --- a/drivers/mmc/host/omap.c +++ b/drivers/mmc/host/omap.c @@ -1276,11 +1276,17 @@ static void mmc_omap_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) OMAP_MMC_WRITE(host, CON, dsor); slot->saved_con = dsor; if (ios->power_mode == MMC_POWER_ON) { + /* worst case at 400kHz, 80 cycles makes 200 microsecs */ + int usecs = 250; + /* Send clock cycles, poll completion */ OMAP_MMC_WRITE(host, IE, 0); OMAP_MMC_WRITE(host, STAT, 0xffff); OMAP_MMC_WRITE(host, CMD, 1 << 7); - while ((OMAP_MMC_READ(host, STAT) & 1) == 0); + while (usecs > 0 && (OMAP_MMC_READ(host, STAT) & 1) == 0) { + udelay(1); + usecs--; + } OMAP_MMC_WRITE(host, STAT, 1); } -- 2.7.4