Date: Fri, 28 Aug 2020 16:40:33 +0000 (UTC) From: Warner Losh <imp@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r364920 - in head/sys: dev/speaker sys Message-ID: <202008281640.07SGeXTb058099@repo.freebsd.org>
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Author: imp Date: Fri Aug 28 16:40:33 2020 New Revision: 364920 URL: https://svnweb.freebsd.org/changeset/base/364920 Log: Remove splclock(). It's not useful to keep. splclock is used in one driver (spkr) to control access to timer_spkr_* routines. However, nothing else does. So it shows no useful locking info to someone that would want to lock spkr. NOTE: I think there's races with timer_spkr_{acquire,release} since there's no interlock in those routines, despite there being a spin lock to protect the clock. Current other users appear to use no extra locking protocol, though they themselves appear to be at least attempting to make sure that only a single thread calls these routines. I suspect the right answer is to update these routines to take/release the clock spin lock since they are short and to the point, but that's beyond the scope of this commit. Modified: head/sys/dev/speaker/spkr.c head/sys/sys/systm.h Modified: head/sys/dev/speaker/spkr.c ============================================================================== --- head/sys/dev/speaker/spkr.c Fri Aug 28 15:35:45 2020 (r364919) +++ head/sys/dev/speaker/spkr.c Fri Aug 28 16:40:33 2020 (r364920) @@ -65,7 +65,7 @@ static void playstring(char *cp, size_t slen); static void tone(unsigned int thz, unsigned int centisecs) { - int sps, timo; + int timo; if (thz <= 0) return; @@ -75,14 +75,10 @@ tone(unsigned int thz, unsigned int centisecs) #endif /* DEBUG */ /* set timer to generate clicks at given frequency in Hertz */ - sps = splclock(); - if (timer_spkr_acquire()) { /* enter list of waiting procs ??? */ - splx(sps); return; } - splx(sps); disable_intr(); timer_spkr_setfreq(thz); enable_intr(); @@ -95,9 +91,7 @@ tone(unsigned int thz, unsigned int centisecs) timo = centisecs * hz / 100; if (timo > 0) tsleep(&endtone, SPKRPRI | PCATCH, "spkrtn", timo); - sps = splclock(); timer_spkr_release(); - splx(sps); } /* Modified: head/sys/sys/systm.h ============================================================================== --- head/sys/sys/systm.h Fri Aug 28 15:35:45 2020 (r364919) +++ head/sys/sys/systm.h Fri Aug 28 16:40:33 2020 (r364920) @@ -497,7 +497,6 @@ void kern_reboot(int) __dead2; void shutdown_nice(int); /* Stubs for obsolete functions that used to be for interrupt management */ -static __inline intrmask_t splclock(void) { return 0; } static __inline intrmask_t splhigh(void) { return 0; } static __inline intrmask_t splimp(void) { return 0; } static __inline intrmask_t splnet(void) { return 0; }
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