From 4d0812c37f2f6cf6fc7ca086b5a5e572cbbe7f6d Mon Sep 17 00:00:00 2001 From: Ohad Ben-Cohen Date: Sun, 14 Nov 2010 12:40:33 +0200 Subject: mmc: sdio: fix nasty oops in mmc_sdio_detect Power off the card in mmc_sdio_detect __before__ a potential error handler, which completely removes the card, executes, and only if the card was successfully powered on beforehand. While we're at it, use the _sync variant of the runtime PM put API, in order to ensure that the card is left powered off in case an error occurred, and the card is going to be removed. Reproduced and tested on the OLPC XO-1.5. Reported-by: Daniel Drake Signed-off-by: Ohad Ben-Cohen Signed-off-by: Chris Ball --- drivers/mmc/core/sdio.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) (limited to 'drivers/mmc/core/sdio.c') diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c index c3ad1058cd31..42a949b723b8 100644 --- a/drivers/mmc/core/sdio.c +++ b/drivers/mmc/core/sdio.c @@ -560,6 +560,19 @@ static void mmc_sdio_detect(struct mmc_host *host) mmc_release_host(host); + /* + * Tell PM core it's OK to power off the card now. + * + * The _sync variant is used in order to ensure that the card + * is left powered off in case an error occurred, and the card + * is going to be removed. + * + * Since there is no specific reason to believe a new user + * is about to show up at this point, the _sync variant is + * desirable anyway. + */ + pm_runtime_put_sync(&host->card->dev); + out: if (err) { mmc_sdio_remove(host); @@ -568,9 +581,6 @@ out: mmc_detach_bus(host); mmc_release_host(host); } - - /* Tell PM core that we're done */ - pm_runtime_put(&host->card->dev); } /* -- cgit v1.2.2 From ed919b0125b26dcc052e44836f66e7e1f5c49c7e Mon Sep 17 00:00:00 2001 From: Ohad Ben-Cohen Date: Fri, 19 Nov 2010 09:29:09 +0200 Subject: mmc: sdio: fix runtime PM anomalies by introducing MMC_CAP_POWER_OFF_CARD 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 Reported-and-tested-by: Arnd Hannemann Signed-off-by: Ohad Ben-Cohen Signed-off-by: Chris Ball --- drivers/mmc/core/sdio.c | 37 +++++++++++++++++++++++-------------- 1 file changed, 23 insertions(+), 14 deletions(-) (limited to 'drivers/mmc/core/sdio.c') diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c index 42a949b723b8..efef5f94ac42 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); -- cgit v1.2.2