Date: Sun, 18 Jun 2017 17:26:54 +0000 (UTC) From: Ian Lepore <ian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r320074 - head/sys/arm/arm Message-ID: <201706181726.v5IHQsAD056026@repo.freebsd.org>
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Author: ian Date: Sun Jun 18 17:26:54 2017 New Revision: 320074 URL: https://svnweb.freebsd.org/changeset/base/320074 Log: Only register as the platform DELAY() implementation if the setup of the global timer was successful, since the implementation tries to read it. Notably, if the platform has a variable-frequency global timer (because of dynamic frequency scaling), it doesn't set up the global timer for use as a system timecounter, and in that case it also can't use it for DELAY. Such platforms use different timer hardware for both timecounter and DELAY. Modified: head/sys/arm/arm/mpcore_timer.c Modified: head/sys/arm/arm/mpcore_timer.c ============================================================================== --- head/sys/arm/arm/mpcore_timer.c Sun Jun 18 17:20:48 2017 (r320073) +++ head/sys/arm/arm/mpcore_timer.c Sun Jun 18 17:26:54 2017 (r320074) @@ -439,7 +439,12 @@ arm_tmr_attach(device_t dev) } #ifdef MULTIDELAY - arm_set_delay(arm_tmr_delay, sc); + /* + * We can register as the DELAY() implementation only if we successfully + * set up the global timer. + */ + if (tc_err == 0) + arm_set_delay(arm_tmr_delay, sc); #endif return (0);
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