Hi Lee, On Wed, 18 Feb 2015, Lee Jones wrote:
> ST's Low Power Controller (LPC) controls two devices; watchdog and RTC. > Only one of the devices can be used at any one time. This is enforced > by the correlating MFD driver. This portion of the driver-set controls > the Real Time Clock. <snip> > +{ > + unsigned long flags; > + > + spin_lock_irqsave(&rtc->lock, flags); > + > + writel(1, rtc->ioaddr + LPC_WDT_OFF); > + > + writel(msb, rtc->ioaddr + LPC_LPA_MSB_OFF); > + writel(lsb, rtc->ioaddr + LPC_LPA_LSB_OFF); > + writel(1, rtc->ioaddr + LPC_LPA_START_OFF); > + > + writel(0, rtc->ioaddr + LPC_WDT_OFF); I think all the writel IO accessors in this driver can be replaced with the *_relaxed variant. This will avoid the overhead of taking a spinlock in the l2 outer cache part of writel. <snip> > +#ifdef CONFIG_PM_SLEEP > +static int st_rtc_suspend(struct device *dev) > +{ > + struct st_rtc *rtc = dev_get_drvdata(dev); > + > + if (device_may_wakeup(dev)) > + return 0; > + > + writel(1, rtc->ioaddr + LPC_WDT_OFF); > + writel(0, rtc->ioaddr + LPC_LPA_START_OFF); > + writel(0, rtc->ioaddr + LPC_WDT_OFF); Is there a reason for not disabling the IP clock in suspend / resume functions? regards, Peter. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/