From 0d3e3350d5871c53464be4c92d57198744247005 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Thu, 4 Apr 2013 16:41:06 +0300 Subject: mmc: core: fix performance regression initializing MMC host controllers Commit fa5501890d8974301042e0202d342a6cbe8609f4 introduced a performance regression by adding mmc_power_up() to mmc_start_host(). mmc_power_up() is not necessary to host controller initialization, it is part of card initialization and is performed anyway asynchronously. This patch allows a driver to leave the power up in asynchronous code (as it was before). On my current target platform this reduces driver initialization from: [ 1.313220] initcall sdhci_acpi_driver_init+0x0/0x12 returned 0 after 102008 usecs to this: [ 1.217209] initcall sdhci_acpi_driver_init+0x0/0x12 returned 0 after 8331 usecs Signed-off-by: Adrian Hunter Acked-by: Ulf Hansson Signed-off-by: Chris Ball --- include/linux/mmc/host.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 17d714801e94..8873e8349597 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -280,6 +280,7 @@ struct mmc_host { #define MMC_CAP2_PACKED_WR (1 << 13) /* Allow packed write */ #define MMC_CAP2_PACKED_CMD (MMC_CAP2_PACKED_RD | \ MMC_CAP2_PACKED_WR) +#define MMC_CAP2_NO_PRESCAN_POWERUP (1 << 14) /* Don't power up before scan */ mmc_pm_flag_t pm_caps; /* supported pm features */ -- cgit v1.2.3-59-g8ed1b