Date: Wed, 18 Aug 2004 09:38:59 +0200 From: dada@sbox.tugraz.at To: FreeBSD problem reports <freebsd-gnats-submit@FreeBSD.org> Subject: i386/70610: [patch] spkr(4): hardcoded assumption HZ == 100 Message-ID: <20040818093859.b0g48oowo4wwkc8k@webmail.tugraz.at> Resent-Message-ID: <200408180740.i7I7eGOQ069788@freefall.freebsd.org>
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>Number: 70610
>Category: i386
>Synopsis: [patch] spkr(4): hardcoded assumption HZ == 100
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-i386
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Wed Aug 18 07:40:16 GMT 2004
>Closed-Date:
>Last-Modified:
>Originator: Martin Kammerhofer
>Release: FreeBSD 4.10-RELEASE-p2 i386
>Organization:
Graz UNI
>Environment:
System: FreeBSD Martin.liebt.Susi 4.10-RELEASE-p2 FreeBSD 4.10-RELEASE-p2 #1: Mon Aug 16 14:26:52 CEST 2004 toor@Martin.liebt.Susi:/mnt/redhat/freebsd/usr/src/sys/compile/GEIDORF4 i386
>Description:
The spkr(4) pseudo-device driver is documented to accept tone
durations in units of 1/100ths of a second. (Cf. spkr(4) and
/usr/include/machine/speaker.h.) However the driver is implemented to
take units of 1/HZ seconds. This mismatch causes timing errors in the
HZ != 100 case.
>How-To-Repeat:
Run a kernel with the speaker(4) pseudo-device and e.g. HZ=400.
Compare times of e.g.:
time /usr/games/morse -p </etc/motd
time /usr/games/morse -d /dev/cuaa0 </etc/motd
>Fix:
--- spkr.c.orig Wed Jun 16 11:47:08 2004
+++ spkr.c Mon Aug 16 16:01:22 2004
@@ -91,18 +91,18 @@
#define SPKRPRI PSOCK
static char endtone, endrest;
-static void tone(unsigned int thz, unsigned int ticks);
-static void rest(int ticks);
+static void tone(unsigned int thz, unsigned int centisecs);
+static void rest(int centisecs);
static void playinit(void);
static void playtone(int pitch, int value, int sustain);
static void playstring(char *cp, size_t slen);
-/* emit tone of frequency thz for given number of ticks */
+/* emit tone of frequency thz for given number of centisecs */
static void
-tone(thz, ticks)
- unsigned int thz, ticks;
+tone(thz, centisecs)
+ unsigned int thz, centisecs;
{
- unsigned int divisor;
+ unsigned int divisor, ticks;
int sps;
if (thz <= 0)
@@ -111,7 +111,7 @@
divisor = timer_freq / thz;
#ifdef DEBUG
- (void) printf("tone: thz=%d ticks=%d\n", thz, ticks);
+ (void) printf("tone: thz=%d centisecs=%d\n", thz, centisecs);
#endif /* DEBUG */
/* set timer to generate clicks at given frequency in Hertz */
@@ -135,6 +135,7 @@
* This is so other processes can execute while the tone is being
* emitted.
*/
+ ticks = centisecs * hz / 100;
if (ticks > 0)
tsleep(&endtone, SPKRPRI | PCATCH, "spkrtn", ticks);
SPEAKER_OFF;
@@ -143,19 +144,22 @@
splx(sps);
}
-/* rest for given number of ticks */
+/* rest for given number of centisecs */
static void
-rest(ticks)
- int ticks;
+rest(centisecs)
+ int centisecs;
{
+ int ticks;
+
/*
* Set timeout to endrest function, then give up the timeslice.
* This is so other processes can execute while the rest is being
* waited out.
*/
#ifdef DEBUG
- (void) printf("rest: %d\n", ticks);
+ (void) printf("rest: %d\n", centisecs);
#endif /* DEBUG */
+ ticks = centisecs * hz / 100;
if (ticks > 0)
tsleep(&endrest, SPKRPRI | PCATCH, "spkrrs", ticks);
}
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>Release-Note:
>Audit-Trail:
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