diff options
author | Jeff Garzik <jgarzik@pobox.com> | 2006-01-03 10:59:55 -0500 |
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committer | Jeff Garzik <jgarzik@pobox.com> | 2006-01-03 10:59:55 -0500 |
commit | 02f693c7118f6be9e677070eb630c1f3a654cdd3 (patch) | |
tree | b5493c816a1f76a01319a84955c5ba07d47517c3 /drivers/mmc/mmc.c | |
parent | e7fb585940a3dc87a42ebc30a62296e5cf6f9cd5 (diff) | |
parent | a18ceba7b40e24a9da87249bd74f16ea5abd6894 (diff) |
Merge branch 'upstream'
Diffstat (limited to 'drivers/mmc/mmc.c')
-rw-r--r-- | drivers/mmc/mmc.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index b586a83a9b4..eb41391e06e 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -679,7 +679,15 @@ static void mmc_idle_cards(struct mmc_host *host) } /* - * Apply power to the MMC stack. + * Apply power to the MMC stack. This is a two-stage process. + * First, we enable power to the card without the clock running. + * We then wait a bit for the power to stabilise. Finally, + * enable the bus drivers and clock to the card. + * + * We must _NOT_ enable the clock prior to power stablising. + * + * If a host does all the power sequencing itself, ignore the + * initial MMC_POWER_UP stage. */ static void mmc_power_up(struct mmc_host *host) { |