Re: [PATCH 0/6] rtc: Fix problems with missing UIE irqs

Esben Haabendal
2024-12-04T08:09:29Z

Esben Haabendal <esben@geanix.com> writes:

> This fixes a couple of different problems, that can cause RTC (alarm)
> irqs to be missing when generating UIE interrupts.
>
> The first commit fixes a long-standing problem, which has been
> documented in a comment since 2010. This fixes a race that could cause
> UIE irqs to stop being generated, which was easily reproduced by
> timing the use of RTC_UIE_ON ioctl with the seconds tick in the RTC.
>
> The last commit ensures that RTC (alarm) irqs are enabled whenever
> RTC_UIE_ON ioctl is used.
>
> The driver specific commits avoids kernel warnings about unbalanced
> enable_irq/disable_irq, which gets triggered on first RTC_UIE_ON with
> the last commit. Before this series, the same warning should be seen
> on initial RTC_AIE_ON with those drivers.

I don't have access to hardware using cpcap, st-lpc or tps6586x rtc
drivers, so I have not been able to test those 3 patches.

/Esben

> Signed-off-by: Esben Haabendal <esben@geanix.com>
> ---
> Esben Haabendal (6):
> rtc: interface: Fix long-standing race when setting alarm
> rtc: isl12022: Fix initial enable_irq/disable_irq balance
> rtc: cpcap: Fix initial enable_irq/disable_irq balance
> rtc: st-lpc: Fix initial enable_irq/disable_irq balance
> rtc: tps6586x: Fix initial enable_irq/disable_irq balance
> rtc: interface: Ensure alarm irq is enabled when UIE is enabled
>
> drivers/rtc/interface.c | 27 +++++++++++++++++++++++++++
> drivers/rtc/rtc-cpcap.c | 1 +
> drivers/rtc/rtc-isl12022.c | 1 +
> drivers/rtc/rtc-st-lpc.c | 1 +
> drivers/rtc/rtc-tps6586x.c | 1 +
> 5 files changed, 31 insertions(+)
> ---
> base-commit: 40384c840ea1944d7c5a392e8975ed088ecf0b37
> change-id: 20241203-rtc-uie-irq-fixes-f2838782d0f8
>
> Best regards,