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@nvidia.com
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@vger.kernel.org
Signed-off-by: Jon Hunter jonathanh@nvidia.com
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.
Cheers Jon