Messages in this thread | | | From | Viresh Kumar <> | Date | Tue, 27 Sep 2016 16:59:22 +0530 | Subject | Re: [PATCH] staging: greybus/timesync: avoid divide by zero on X86 Qemu |
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On Mon, Sep 26, 2016 at 10:31 PM, Bryan O'Donoghue <pure.logic@nexus-software.ie> wrote: > A system configured without CONFIG_CPUFREQ will return 0 for cpufreq_get(). > greybus-timesync can subsequently then do a divide-by-zero as result. This > patch fixes by checking for a zero return value from cpufreq_get() and > setting to a default value of 19.2MHz. > > Reported-by: Rui Miguel Silva <rmfrfs@gmail.com> > Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie> > --- > drivers/staging/greybus/timesync_platform.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/drivers/staging/greybus/timesync_platform.c b/drivers/staging/greybus/timesync_platform.c > index 50e8883..113f3d6 100644 > --- a/drivers/staging/greybus/timesync_platform.c > +++ b/drivers/staging/greybus/timesync_platform.c > @@ -20,6 +20,8 @@ > #include "greybus.h" > #include "arche_platform.h" > > +#define DEFAULT_FRAMETIME_CLOCK_HZ 19200000 > + > static u32 gb_timesync_clock_frequency; > int (*arche_platform_change_state_cb)(enum arche_platform_state state, > struct gb_timesync_svc *pdata); > @@ -32,8 +34,11 @@ u64 gb_timesync_platform_get_counter(void) > > u32 gb_timesync_platform_get_clock_rate(void) > { > - if (unlikely(!gb_timesync_clock_frequency)) > - return cpufreq_get(0); > + if (unlikely(!gb_timesync_clock_frequency)) { > + gb_timesync_clock_frequency = cpufreq_get(0); > + if (!gb_timesync_clock_frequency) > + gb_timesync_clock_frequency = DEFAULT_FRAMETIME_CLOCK_HZ; > + } > > return gb_timesync_clock_frequency; > }
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
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