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| author | Adrian Hunter <adrian.hunter@intel.com> | 2013-04-04 13:41:06 (GMT) |
|---|---|---|
| committer | Chris Ball <cjb@laptop.org> | 2013-04-12 18:08:07 (GMT) |
| commit | 0d3e3350d5871c53464be4c92d57198744247005 (patch) | |
| tree | cca13f8eb12a397c4ea8adf9f74de3bcd7c89041 /drivers/mmc/host/sdhci-acpi.c | |
| parent | f9a94e0a3f18ae4c0245d4a16d0ee20e93fd7bad (diff) | |
| download | linux-0d3e3350d5871c53464be4c92d57198744247005.tar.xz | |
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/sdhci-acpi.c')
| -rw-r--r-- | drivers/mmc/host/sdhci-acpi.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c index 2592ddd..7bcf74b 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; |