On 10/24/18 1:49 PM, Jon Hunter wrote: > > On 22/10/2018 12:19, Dmitry Osipenko wrote: >> On 10/22/18 12:52 PM, Thierry Reding wrote: >>> On Fri, Oct 19, 2018 at 02:22:53PM +0100, Jon Hunter wrote: >>>> From: Jonathan Hunter <jonathanh@xxxxxxxxxx> >>>> >>>> The tps6586x driver creates an irqchip that is used by its various child >>>> devices for managing interrupts. The tps6586x-rtc device is one of its >>>> children that uses the tps6586x irqchip. When using the tps6586x-rtc as >>>> a wake-up device from suspend, the following is seen: >>>> >>>> PM: Syncing filesystems ... done. >>>> Freezing user space processes ... (elapsed 0.001 seconds) done. >>>> OOM killer disabled. >>>> Freezing remaining freezable tasks ... (elapsed 0.000 seconds) done. >>>> Disabling non-boot CPUs ... >>>> Entering suspend state LP1 >>>> Enabling non-boot CPUs ... >>>> CPU1 is up >>>> tps6586x 3-0034: failed to read interrupt status >>>> tps6586x 3-0034: failed to read interrupt status >>>> >>>> The reason why the tps6586x interrupt status cannot be read is because >>>> the tps6586x interrupt is not masked during suspend and when the >>>> tps6586x-rtc interrupt occurs, to wake-up the device, the interrupt is >>>> seen before the i2c controller has been resumed in order to read the >>>> tps6586x interrupt status. >>>> >>>> The tps6586x-rtc driver sets it's interrupt as a wake-up source during >>>> suspend, which gets propagated to the parent tps6586x interrupt. >>>> However, the tps6586x-rtc driver cannot disable it's interrupt during >>>> suspend otherwise we would never be woken up and so the tps6586x must >>>> disable it's interrupt instead. >>>> >>>> Prevent the tps6586x interrupt handler from executing on exiting suspend >>>> before the i2c controller has been resumed by disabling the tps6586x >>>> interrupt on entering suspend and re-enabling it on resuming from >>>> suspend. >>>> >>>> Cc: stable@xxxxxxxxxxxxxxx >>>> >>>> Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx> >>>> --- >>>> drivers/mfd/tps6586x.c | 24 ++++++++++++++++++++++++ >>>> 1 file changed, 24 insertions(+) >>> >>> So does this mean that the SPI interrupt for the PMIC can still be a >>> wakeup source even if it is masked? This is slightly odd because now >>> you're saying that this does work while it doesn't work for the RTC >>> interrupt. So is this an implementation quirk of the LIC/GIC on Tegra >>> which doesn't extend to the TPS6586x? Or am I missing something? >> >> What is the expected behaviour of IRQ disabling? Should it disable wakeup ability or only mask IRQ handling? > > I believe only mask the interrupt. However, the caveat here could be if > the parent interrupt controller actually supports wake-up. For Tegra it > is the LIC that handles the wake-up. > >> Couple months ago disabling of IRQ was disabling the wakeup, now something has been changed in kernel and wakeup isn't getting disabled. So either there was a bug before that was fixed or there is a bug now. > > Are you sure you were disabling the PMIC host interrupt? If you disable > the RTC interrupt in the PMIC's RTC driver, then this will prevent the > wake-up from occurring because you are masking the interrupt within the > PMIC and so it will never generate an interrupt to the host. I'm pretty sure (but not 100%) that was trying the same change as in your patch and it didn't work sometime before. If disable_irq() shouldn't disable wakeup, then everything is perfect now.
