On Wed, Jul 29, 2015 at 8:02 AM, Leo Yan <[email protected]> wrote: > When use rtc-pl031 for suspend test on Hisilicon's SoC Hi6220, Usually > the data register (DR) will read back as value zero. So the suspend > test code will set the match register (MR) for 10 seconds' timeout; But > there have chance later will read back some random values from DR > register; So finally miss with match value and will not trigger > waken up event anymore. > > This issue can be dismissed by reset registers in initialization flow; > And this code have no harm for ST's variant. > > Signed-off-by: Leo Yan <[email protected]>
I don't understand this... > + /* Init registers */ > + writel(0x0, ldata->base + RTC_LR); This will reset the clock to jan 1st 1970 on every reboot. The idea is that the RTC should *preserve* the system time if you reboot the system, so NACK. Usually userspace has a script using hwclock to read the system time from the rtc to system time with hwclock -s after userspace comes up. Likewise it writes it back with hwclock -w before rebooting. > + writel(0x0, ldata->base + RTC_DR); This is a read-only register in the PL031 clean variant. What do you want to achieve here? Is this register writeable on the HiSilicon? > + writel(0x0, ldata->base + RTC_IMSC); OK > + writel(RTC_BIT_AI, ldata->base + RTC_ICR); So why do we want to have the alarm enabled by default, before the kernel nor userspace has requested it? If your problem is with suspend/resume I suggest you work on the [runtime]_suspend/resume hooks instead of probe(). Possibly you need to save/restore state across suspend/resume. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
