[PATCH 4/8] mmc: mmci: Use ios_handler to save power
From: Vitaly Wool <hidden>
Date: 2012-04-18 11:57:27
Also in:
linux-mmc
Hi Ulf, On Tue, Jan 17, 2012 at 3:34 PM, Ulf Hansson [off-list ref] wrote:
quoted hunk ↗ jump to hunk
To disable a levelshifter when we are in an idle state will decrease current consumption. We make use of the ios_handler at runtime suspend and at regular suspend to accomplish this. Of course depending on the used levelshifter the decrease of current differs. For ST6G3244ME the value is up to ~200 uA. Tested-by: Linus Walleij <redacted> Signed-off-by: Ulf Hansson <redacted> Signed-off-by: Linus Walleij <redacted> --- ?drivers/mmc/host/mmci.c | ? 19 ++++++++++++++++++- ?1 files changed, 18 insertions(+), 1 deletions(-)diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c index a7c8f8f..76ce2cd 100644 --- a/drivers/mmc/host/mmci.c +++ b/drivers/mmc/host/mmci.c@@ -1505,10 +1505,22 @@ static int mmci_save(struct amba_device *dev)?{ ? ? ? ?struct mmc_host *mmc = amba_get_drvdata(dev); ? ? ? ?unsigned long flags; + ? ? ? struct mmc_ios ios; + ? ? ? int ret = 0; ? ? ? ?if (mmc) { ? ? ? ? ? ? ? ?struct mmci_host *host = mmc_priv(mmc); + ? ? ? ? ? ? ? /* Let the ios_handler act on a POWER_OFF to save power. */ + ? ? ? ? ? ? ? if (host->plat->ios_handler) { + ? ? ? ? ? ? ? ? ? ? ? memcpy(&ios, &mmc->ios, sizeof(struct mmc_ios)); + ? ? ? ? ? ? ? ? ? ? ? ios.power_mode = MMC_POWER_OFF; + ? ? ? ? ? ? ? ? ? ? ? ret = host->plat->ios_handler(mmc_dev(mmc), + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? &ios); + ? ? ? ? ? ? ? ? ? ? ? if (ret) + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? return ret; + ? ? ? ? ? ? ? } + ? ? ? ? ? ? ? ?spin_lock_irqsave(&host->lock, flags); ? ? ? ? ? ? ? ?/*@@ -1527,7 +1539,7 @@ static int mmci_save(struct amba_device *dev)? ? ? ? ? ? ? ?amba_vcore_disable(dev); ? ? ? ?} - ? ? ? return 0; + ? ? ? return ret; ?} ?static int mmci_restore(struct amba_device *dev)@@ -1550,6 +1562,11 @@ static int mmci_restore(struct amba_device *dev)? ? ? ? ? ? ? ?writel(MCI_IRQENABLE, host->base + MMCIMASK0); ? ? ? ? ? ? ? ?spin_unlock_irqrestore(&host->lock, flags); + + ? ? ? ? ? ? ? /* Restore settings done by the ios_handler. */ + ? ? ? ? ? ? ? if (host->plat->ios_handler) + ? ? ? ? ? ? ? ? ? ? ? host->plat->ios_handler(mmc_dev(mmc), + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? &mmc->ios); ? ? ? ?} ? ? ? ?return 0;
this patch is a disaster because it cuts off the chip's power on suspend regardless of whether MMC_PM_KEEP_POWER flag has been set or not. Simply put: it breaks everything This patch therefore gets a strongest *NACK* from me. Thanks, Vitaly