diff options
| author | Len Brown <len.brown@intel.com> | 2005-12-15 13:15:27 -0500 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2005-12-15 13:15:27 -0500 |
| commit | 5b2db367a28c12e8dfd0b404d9ea35e948c5d7b3 (patch) | |
| tree | 8ef2f739fc91acda0fb05797cb450b5789d79c59 /drivers/mmc | |
| parent | d3e4cefc86ce1aefc0e9aebdc56308cb4bd51997 (diff) | |
| parent | 7116317dc9148d783846299fc80a7d377baa6dca (diff) | |
Auto-update from upstream
Diffstat (limited to 'drivers/mmc')
| -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) { |