Some board/card/host configurations are not capable of powering off the card after boot.
To support such configurations, and to allow smoother transition to runtime PM behavior, MMC_CAP_POWER_OFF_CARD is added, so hosts need to explicitly indicate whether it's OK to power off their cards after boot. SDIO core will enable runtime PM for a card only if that cap is set. As a result, the card will be powered down after boot, and will only be powered up again when a driver is loaded (and then it's up to the driver to decide whether power will be kept or not). This will prevent sdio_bus_probe() failures with setups that do not support powering off the card. Reported-and-tested-by: Daniel Drake <[email protected]> Reported-and-tested-by: Arnd Hannemann <[email protected]> Signed-off-by: Ohad Ben-Cohen <[email protected]> --- This is a second fix intended to 2.6.37 (first one is at https://patchwork.kernel.org/patch/323182/). It depends on the first one and cannot be applied independently. drivers/mmc/core/sdio.c | 37 +++++++++++++++++++++++-------------- drivers/mmc/core/sdio_bus.c | 33 ++++++++++++++++++++++----------- include/linux/mmc/host.h | 1 + 3 files changed, 46 insertions(+), 25 deletions(-) diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c index 42a949b..efef5f9 100644 --- a/drivers/mmc/core/sdio.c +++ b/drivers/mmc/core/sdio.c @@ -547,9 +547,11 @@ static void mmc_sdio_detect(struct mmc_host *host) BUG_ON(!host->card); /* Make sure card is powered before detecting it */ - err = pm_runtime_get_sync(&host->card->dev); - if (err < 0) - goto out; + if (host->caps & MMC_CAP_POWER_OFF_CARD) { + err = pm_runtime_get_sync(&host->card->dev); + if (err < 0) + goto out; + } mmc_claim_host(host); @@ -571,7 +573,8 @@ static void mmc_sdio_detect(struct mmc_host *host) * is about to show up at this point, the _sync variant is * desirable anyway. */ - pm_runtime_put_sync(&host->card->dev); + if (host->caps & MMC_CAP_POWER_OFF_CARD) + pm_runtime_put_sync(&host->card->dev); out: if (err) { @@ -728,16 +731,21 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr) card = host->card; /* - * Let runtime PM core know our card is active + * Enable runtime PM only if supported by host+card+board */ - err = pm_runtime_set_active(&card->dev); - if (err) - goto remove; + if (host->caps & MMC_CAP_POWER_OFF_CARD) { + /* + * Let runtime PM core know our card is active + */ + err = pm_runtime_set_active(&card->dev); + if (err) + goto remove; - /* - * Enable runtime PM for this card - */ - pm_runtime_enable(&card->dev); + /* + * Enable runtime PM for this card + */ + pm_runtime_enable(&card->dev); + } /* * The number of functions on the card is encoded inside @@ -755,9 +763,10 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr) goto remove; /* - * Enable Runtime PM for this func + * Enable Runtime PM for this func (if supported) */ - pm_runtime_enable(&card->sdio_func[i]->dev); + if (host->caps & MMC_CAP_POWER_OFF_CARD) + pm_runtime_enable(&card->sdio_func[i]->dev); } mmc_release_host(host); diff --git a/drivers/mmc/core/sdio_bus.c b/drivers/mmc/core/sdio_bus.c index 2716c7a..203da44 100644 --- a/drivers/mmc/core/sdio_bus.c +++ b/drivers/mmc/core/sdio_bus.c @@ -17,6 +17,7 @@ #include <linux/pm_runtime.h> #include <linux/mmc/card.h> +#include <linux/mmc/host.h> #include <linux/mmc/sdio_func.h> #include "sdio_cis.h" @@ -132,9 +133,11 @@ static int sdio_bus_probe(struct device *dev) * it should call pm_runtime_put_noidle() in its probe routine and * pm_runtime_get_noresume() in its remove routine. */ - ret = pm_runtime_get_sync(dev); - if (ret < 0) - goto out; + if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD) { + ret = pm_runtime_get_sync(dev); + if (ret < 0) + goto out; + } /* Set the default block size so the driver is sure it's something * sensible. */ @@ -151,7 +154,8 @@ static int sdio_bus_probe(struct device *dev) return 0; disable_runtimepm: - pm_runtime_put_noidle(dev); + if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD) + pm_runtime_put_noidle(dev); out: return ret; } @@ -160,12 +164,14 @@ static int sdio_bus_remove(struct device *dev) { struct sdio_driver *drv = to_sdio_driver(dev->driver); struct sdio_func *func = dev_to_sdio_func(dev); - int ret; + int ret = 0; /* Make sure card is powered before invoking ->remove() */ - ret = pm_runtime_get_sync(dev); - if (ret < 0) - goto out; + if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD) { + ret = pm_runtime_get_sync(dev); + if (ret < 0) + goto out; + } drv->remove(func); @@ -178,10 +184,12 @@ static int sdio_bus_remove(struct device *dev) } /* First, undo the increment made directly above */ - pm_runtime_put_noidle(dev); + if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD) + pm_runtime_put_noidle(dev); /* Then undo the runtime PM settings in sdio_bus_probe() */ - pm_runtime_put_noidle(dev); + if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD) + pm_runtime_put_noidle(dev); out: return ret; @@ -191,6 +199,8 @@ out: static int sdio_bus_pm_prepare(struct device *dev) { + struct sdio_func *func = dev_to_sdio_func(dev); + /* * Resume an SDIO device which was suspended at run time at this * point, in order to allow standard SDIO suspend/resume paths @@ -212,7 +222,8 @@ static int sdio_bus_pm_prepare(struct device *dev) * since there is little point in failing system suspend if a * device can't be resumed. */ - pm_runtime_resume(dev); + if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD) + pm_runtime_resume(dev); return 0; } diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 53496bb..381c77f 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -168,6 +168,7 @@ struct mmc_host { /* DDR mode at 1.8V */ #define MMC_CAP_1_2V_DDR (1 << 12) /* can support */ /* DDR mode at 1.2V */ +#define MMC_CAP_POWER_OFF_CARD (1 << 13) /* Can power off after boot */ mmc_pm_flag_t pm_caps; /* supported pm features */ -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
