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path: root/drivers/mmc/mmc.c
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Diffstat (limited to 'drivers/mmc/mmc.c')
-rw-r--r--drivers/mmc/mmc.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index d336a1d65dc7..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)
{
@@ -932,8 +940,9 @@ static void mmc_read_scrs(struct mmc_host *host)
sg_init_one(&sg, (u8*)card->raw_scr, 8);
- err = mmc_wait_for_req(host, &mrq);
- if (err != MMC_ERR_NONE) {
+ mmc_wait_for_req(host, &mrq);
+
+ if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE) {
mmc_card_set_dead(card);
continue;
}