| Message ID | 1476358660-8338-7-git-send-email-ulf.hansson@linaro.org |
|---|---|
| State | New |
| Headers | show |
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 2553d90..2ad7291 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -2824,12 +2824,11 @@ void mmc_start_host(struct mmc_host *host) host->rescan_disable = 0; host->ios.power_mode = MMC_POWER_UNDEFINED; - mmc_claim_host(host); - if (host->caps2 & MMC_CAP2_NO_PRESCAN_POWERUP) - mmc_power_off(host); - else + if (!(host->caps2 & MMC_CAP2_NO_PRESCAN_POWERUP)) { + mmc_claim_host(host); mmc_power_up(host, host->ocr_avail); - mmc_release_host(host); + mmc_release_host(host); + } mmc_gpiod_request_cd_irq(host); _mmc_detect_change(host, 0, false);
The MMC_CAP2_NO_PRESCAN_POWERUP was invented to avoid running the power up sequence, mmc_power_up(), during ->probe() of the mmc host driver, but instead defer this to the mmc detect work. This is especially useful for those hosts that suffers from a long initialization time, as this time would otherwise add up to the total boot time. However, due to the introduction of runtime PM of mmc host devices in the mmc core, this behaviour changed a bit. More precisely, it caused the mmc core to runtime resume the host device during ->probe() of the host driver. In cases like the rtsx_usb_sdmmc, runtime resuming the device may be costly and thus affecting the total boot time. To improve this behaviour when using MMC_CAP2_NO_PRESCAN_POWERUP, let's postpone also calling mmc_power_off() when starting the host. This change allows the mmc core to avoid runtime resuming the device, as it don't need to claim the host for that execution path. Cc: Ritesh Raj Sarraf <rrs@researchut.com> Cc: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> --- drivers/mmc/core/core.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) -- 1.9.1