From: Bryan O'Donoghue Date: Mon, 26 Sep 2016 17:01:23 +0000 (+0100) Subject: staging: greybus/timesync: avoid divide by zero on X86 Qemu X-Git-Tag: v4.9-rc1~119^2~189 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=659849cdc065c3620e49f9a7dbc384669f4592ab;p=karo-tx-linux.git staging: greybus/timesync: avoid divide by zero on X86 Qemu 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 Signed-off-by: Bryan O'Donoghue Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/greybus/timesync_platform.c b/drivers/staging/greybus/timesync_platform.c index 50e8883f932f..113f3d6c4b3a 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; }