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| author | Linus Torvalds <torvalds@g5.osdl.org> | 2005-12-15 00:46:46 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-12-15 00:46:46 +0100 |
| commit | 9d149c27eb1581edd239c0db96a407a4fc5e9f18 (patch) | |
| tree | 7e1b98ed7c681baff2bb863046d8b1ac9733efa7 | |
| parent | [IA64] fix for SET_PERSONALITY when CONFIG_IA32_SUPPORT is not set. (diff) | |
| parent | [MMC] Explain the internals of mmc_power_up() (diff) | |
| download | linux-9d149c27eb1581edd239c0db96a407a4fc5e9f18.tar.xz linux-9d149c27eb1581edd239c0db96a407a4fc5e9f18.zip | |
Merge master.kernel.org:/home/rmk/linux-2.6-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 b586a83a9b4c..eb41391e06e9 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) { |