Re: [PATCH v4] rtc: pcf2127: handle timestamp interrupts

From: Mian Yousaf Kaukab
Date: Thu May 27 2021 - 10:23:46 EST


On Tue, May 25, 2021 at 12:11:07PM +0200, Mian Yousaf Kaukab wrote:
> commit 03623b4b041c ("rtc: pcf2127: add tamper detection support")
> added support for timestamp interrupts. However they are not being
> handled in the irq handler. If a timestamp interrupt occurs it
> results in kernel disabling the interrupt and displaying the call
> trace:
>
> [ 121.145580] irq 78: nobody cared (try booting with the "irqpoll" option)
> ...
> [ 121.238087] [<00000000c4d69393>] irq_default_primary_handler threaded [<000000000a90d25b>] pcf2127_rtc_irq [rtc_pcf2127]
> [ 121.248971] Disabling IRQ #78
>
> Handle timestamp interrupts in pcf2127_rtc_irq(). Save time stamp
> before clearing TSF1 and TSF2 flags so that it can't be overwritten.
> Set a flag to mark if the timestamp is valid and only report to sysfs
> if the flag is set. To mimic the hardware behavior, don’t save
> another timestamp until the first one has been read by the userspace.
Alexandre, I hope this patch addresses all your concerns. Please let
me know if thats not the case.

BR,
Yousaf