Date: Sat, 19 Nov 2011 11:17:28 +0000 (UTC) From: Hans Petter Selasky <hselasky@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r227706 - in head/sys: dev/usb kern Message-ID: <201111191117.pAJBHSXC039923@svn.freebsd.org>
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Author: hselasky Date: Sat Nov 19 11:17:27 2011 New Revision: 227706 URL: http://svn.freebsd.org/changeset/base/227706 Log: Simplify the usb_pause_mtx() function by factoring out the generic parts to the kernel's pause() function. The pause() function can now be used when cold != 0. Also assert that the timeout in system ticks must be positive. Suggested by: Bruce Evans MFC after: 1 week Modified: head/sys/dev/usb/usb_util.c head/sys/kern/kern_synch.c Modified: head/sys/dev/usb/usb_util.c ============================================================================== --- head/sys/dev/usb/usb_util.c Sat Nov 19 10:49:03 2011 (r227705) +++ head/sys/dev/usb/usb_util.c Sat Nov 19 11:17:27 2011 (r227706) @@ -115,33 +115,21 @@ device_set_usb_desc(device_t dev) * * This function will delay the code by the passed number of system * ticks. The passed mutex "mtx" will be dropped while waiting, if - * "mtx" is not NULL. + * "mtx" is different from NULL. *------------------------------------------------------------------------*/ void -usb_pause_mtx(struct mtx *mtx, int _ticks) +usb_pause_mtx(struct mtx *mtx, int timo) { if (mtx != NULL) mtx_unlock(mtx); - if (cold) { - /* convert to milliseconds */ - _ticks = (_ticks * 1000) / hz; - /* convert to microseconds, rounded up */ - _ticks = (_ticks + 1) * 1000; - DELAY(_ticks); - - } else { - - /* - * Add one to the number of ticks so that we don't return - * too early! - */ - _ticks++; - - if (pause("USBWAIT", _ticks)) { - /* ignore */ - } - } + /* + * Add one tick to the timeout so that we don't return too + * early! Note that pause() will assert that the passed + * timeout is positive and non-zero! + */ + pause("USBWAIT", timo + 1); + if (mtx != NULL) mtx_lock(mtx); } Modified: head/sys/kern/kern_synch.c ============================================================================== --- head/sys/kern/kern_synch.c Sat Nov 19 10:49:03 2011 (r227705) +++ head/sys/kern/kern_synch.c Sat Nov 19 11:17:27 2011 (r227706) @@ -325,16 +325,34 @@ msleep_spin(void *ident, struct mtx *mtx } /* - * pause() is like tsleep() except that the intention is to not be - * explicitly woken up by another thread. Instead, the current thread - * simply wishes to sleep until the timeout expires. It is - * implemented using a dummy wait channel. + * pause() is almost like tsleep() except that the intention is to not + * be explicitly woken up by another thread. Instead, the current + * thread simply wishes to sleep until the timeout expires. It is + * implemented using a dummy wait channel. During cold bootup pause() + * will use the DELAY() function instead of tsleep() to wait the given + * number of system ticks. The passed "timo" argument must not be + * negative and also greater than zero. */ int pause(const char *wmesg, int timo) { - KASSERT(timo != 0, ("pause: timeout required")); + KASSERT(timo > 0, ("pause: a positive and non-zero " + "timeout is required")); + + if (cold) { + /* + * We delay one HZ at a time to avoid overflowing the + * DELAY() argument: + */ + while (timo >= hz) { + DELAY(1000000); + timo -= hz; + } + if (timo > 0) + DELAY(timo * tick); + return (0); + } return (tsleep(&pause_wchan, 0, wmesg, timo)); }
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