path: root/drivers/mmc/host
diff options
authorAdrian Hunter <adrian.hunter@intel.com>2013-04-04 16:41:06 +0300
committerChris Ball <cjb@laptop.org>2013-04-12 14:08:07 -0400
commit0d3e3350d5871c53464be4c92d57198744247005 (patch)
treecca13f8eb12a397c4ea8adf9f74de3bcd7c89041 /drivers/mmc/host
parentf9a94e0a3f18ae4c0245d4a16d0ee20e93fd7bad (diff)
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 <adrian.hunter@intel.com> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc/host')
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c
index 2592dddbd96..7bcf74b1a5c 100644
--- a/drivers/mmc/host/sdhci-acpi.c
+++ b/drivers/mmc/host/sdhci-acpi.c
@@ -195,6 +195,8 @@ static int sdhci_acpi_probe(struct platform_device *pdev)
host->mmc->pm_caps |= c->slot->pm_caps;
+ host->mmc->caps2 |= MMC_CAP2_NO_PRESCAN_POWERUP;
err = sdhci_add_host(host);
if (err)
goto err_free;