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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