Messages in this thread | | | Date | Fri, 20 Oct 2017 09:49:00 +0200 (CEST) | From | David Kozub <> | Subject | Re: [PATCH] clockevents/drivers/cs5535: improve resilience to spurious interrupts |
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On Fri, 20 Oct 2017, Daniel Lezcano wrote:
> On 20/10/2017 00:25, Thomas Gleixner wrote: >> On Fri, 20 Oct 2017, Daniel Lezcano wrote: >> >>> On 19/10/2017 22:57, David Kozub wrote: >>>> This solves a BUG on ALIX 2c3 where mfgpt_tick is called before >>>> clockevents_config_and_register returns. This caused mfgpt_tick to call a >>>> null function pointer. >>>> >>>> Thanks to Daniel Lezcano and Thomas Gleixner for helping me analyze this >>>> and suggesting a solution. >>>> >>>> Suggested-by: Thomas Gleixner <tglx@linutronix.de> >>>> Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz> >>>> --- >>> >>> Thank for sending this fix. >>> >>> Can you check if the commit 8f9327cbb is the one introducing the >>> regression ? So we can add the proper tags and propagate the fix to stable. >> >> No it's not. >> >> - if (cs5535_tick_mode == CLOCK_EVT_MODE_SHUTDOWN) >> + if (clockevent_state_shutdown(&cs5535_clockevent)) >> >> This particular problem of the missing detached state check has been there >> forever and went unnoticed for whatever reason. > > The detached condition was artificially caught by the initialized variable: > > -static unsigned int cs5535_tick_mode = CLOCK_EVT_MODE_SHUTDOWN; > > The patch 8f9327cbb removes the variable, so very likely this is where > the problem appeared.
I will try to test that. But I won't have access to the device till Sunday evening. I've had big trouble trying to run kernels > 4.1-rc5 on the device and if I'm looking correctly the commit was introduced in 4.3-rc1. But I'll try to figure something out.
Best regards, David
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