diff options
| author | Pierre Ossman <drzeus@drzeus.cx> | 2007-09-19 18:38:50 +0200 |
|---|---|---|
| committer | Pierre Ossman <drzeus@drzeus.cx> | 2007-09-23 21:26:06 +0200 |
| commit | f9996aee36921e8f1d499de1b2ea380855cf6d97 (patch) | |
| tree | 159358eb9fa65da8997f7122fcae1c57ae948bb2 /drivers | |
| parent | f75979b77fb20b01522d8fab96dfc76cc9f42420 (diff) | |
| download | linux-f9996aee36921e8f1d499de1b2ea380855cf6d97.tar.bz2 | |
mmc: increase power up delay
Increase delay for power up in order to support some slower boards.
Also add some comments about why the delays are there.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/mmc/core/core.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 3bebd3b55dc5..bffcaf8df352 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -460,12 +460,20 @@ static void mmc_power_up(struct mmc_host *host) host->ios.timing = MMC_TIMING_LEGACY; mmc_set_ios(host); - mmc_delay(1); + /* + * This delay should be sufficient to allow the power supply + * to reach the minimum voltage. + */ + mmc_delay(2); host->ios.clock = host->f_min; host->ios.power_mode = MMC_POWER_ON; mmc_set_ios(host); + /* + * This delay must be at least 74 clock sizes, or 1 ms, or the + * time required to reach a stable voltage. + */ mmc_delay(2); } |