| Message ID | 515ED220.5050105@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 5 April 2013 15:31, Adrian Hunter <adrian.hunter@intel.com> wrote: > Commit fa5501890d8974301042e0202d342a6cbe8609f4 introduced a boot time > 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. > Please see the original commit for an explanation of the use of > mmc_power_up() in mmc_start_host(). > > 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> > --- > drivers/mmc/core/core.c | 3 ++- > drivers/mmc/host/sdhci-acpi.c | 2 ++ > include/linux/mmc/host.h | 1 + > 3 files changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c > index 3bf1c46..c1893c9 100644 > --- a/drivers/mmc/core/core.c > +++ b/drivers/mmc/core/core.c > @@ -2416,7 +2416,8 @@ void mmc_start_host(struct mmc_host *host) > { > host->f_init = max(freqs[0], host->f_min); > host->rescan_disable = 0; > - mmc_power_up(host); > + if (!(host->caps2 & MMC_CAP2_NO_PRESCAN_POWERUP)) > + mmc_power_up(host); > mmc_detect_change(host, 0); > } > > 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; > diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h > index 17d7148..8873e83 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 */ > > -- > 1.7.11.7 > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html Acked-by: Ulf Hansson <ulf.hansson@linaro.org> -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 3bf1c46..c1893c9 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -2416,7 +2416,8 @@ void mmc_start_host(struct mmc_host *host) { host->f_init = max(freqs[0], host->f_min); host->rescan_disable = 0; - mmc_power_up(host); + if (!(host->caps2 & MMC_CAP2_NO_PRESCAN_POWERUP)) + mmc_power_up(host); mmc_detect_change(host, 0); } 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; diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 17d7148..8873e83 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 */
Commit fa5501890d8974301042e0202d342a6cbe8609f4 introduced a boot time 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. Please see the original commit for an explanation of the use of mmc_power_up() in mmc_start_host(). 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> --- drivers/mmc/core/core.c | 3 ++- drivers/mmc/host/sdhci-acpi.c | 2 ++ include/linux/mmc/host.h | 1 + 3 files changed, 5 insertions(+), 1 deletion(-)