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authorPierre Ossman <drzeus@drzeus.cx>2007-09-19 12:38:50 -0400
committerPierre Ossman <drzeus@drzeus.cx>2007-09-23 15:26:06 -0400
commitf9996aee36921e8f1d499de1b2ea380855cf6d97 (patch)
tree159358eb9fa65da8997f7122fcae1c57ae948bb2 /drivers/mmc/core
parentf75979b77fb20b01522d8fab96dfc76cc9f42420 (diff)
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/mmc/core')
-rw-r--r--drivers/mmc/core/core.c10
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)
460 host->ios.timing = MMC_TIMING_LEGACY; 460 host->ios.timing = MMC_TIMING_LEGACY;
461 mmc_set_ios(host); 461 mmc_set_ios(host);
462 462
463 mmc_delay(1); 463 /*
464 * This delay should be sufficient to allow the power supply
465 * to reach the minimum voltage.
466 */
467 mmc_delay(2);
464 468
465 host->ios.clock = host->f_min; 469 host->ios.clock = host->f_min;
466 host->ios.power_mode = MMC_POWER_ON; 470 host->ios.power_mode = MMC_POWER_ON;
467 mmc_set_ios(host); 471 mmc_set_ios(host);
468 472
473 /*
474 * This delay must be at least 74 clock sizes, or 1 ms, or the
475 * time required to reach a stable voltage.
476 */
469 mmc_delay(2); 477 mmc_delay(2);
470} 478}
471 479