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sysmon_envsys_events.c revision 1.26
      1 /* $NetBSD: sysmon_envsys_events.c,v 1.26 2007/09/01 00:12:07 xtraeme Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2007 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Juan Romero Pardines.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *      This product includes software developed by Juan Romero Pardines
     21  *      for the NetBSD Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 /*
     40  * sysmon_envsys(9) events framework.
     41  */
     42 
     43 #include <sys/cdefs.h>
     44 __KERNEL_RCSID(0, "$NetBSD: sysmon_envsys_events.c,v 1.26 2007/09/01 00:12:07 xtraeme Exp $");
     45 
     46 #include <sys/param.h>
     47 #include <sys/types.h>
     48 #include <sys/conf.h>
     49 #include <sys/errno.h>
     50 #include <sys/kernel.h>
     51 #include <sys/sysctl.h>
     52 #include <sys/systm.h>
     53 #include <sys/proc.h>
     54 #include <sys/mutex.h>
     55 #include <sys/kmem.h>
     56 #include <sys/callout.h>
     57 
     58 #include <dev/sysmon/sysmonvar.h>
     59 #include <dev/sysmon/sysmon_envsysvar.h>
     60 
     61 struct sme_sensor_state {
     62 	int		type;
     63 	const char 	*desc;
     64 };
     65 
     66 struct sme_sensor_event {
     67 	int		state;
     68 	int		event;
     69 };
     70 
     71 static const struct sme_sensor_state sme_sensor_drive_state[] = {
     72 	{ ENVSYS_DRIVE_EMPTY, 		"drive state is unknown" },
     73 	{ ENVSYS_DRIVE_READY, 		"drive is ready" },
     74 	{ ENVSYS_DRIVE_POWERUP,		"drive is powering up" },
     75 	{ ENVSYS_DRIVE_ONLINE, 		"drive is online" },
     76 	{ ENVSYS_DRIVE_IDLE, 		"drive is idle" },
     77 	{ ENVSYS_DRIVE_ACTIVE, 		"drive is active" },
     78 	{ ENVSYS_DRIVE_REBUILD, 	"drive is rebuilding" },
     79 	{ ENVSYS_DRIVE_POWERDOWN,	"drive is powering down" },
     80 	{ ENVSYS_DRIVE_FAIL, 		"drive failed" },
     81 	{ ENVSYS_DRIVE_PFAIL,		"drive degraded" },
     82 	{ -1, 				"unknown" }
     83 };
     84 
     85 static const struct sme_sensor_event sme_sensor_event[] = {
     86 	{ ENVSYS_SVALID, 	PENVSYS_EVENT_NORMAL },
     87 	{ ENVSYS_SCRITICAL, 	PENVSYS_EVENT_CRITICAL },
     88 	{ ENVSYS_SCRITOVER, 	PENVSYS_EVENT_CRITOVER },
     89 	{ ENVSYS_SCRITUNDER, 	PENVSYS_EVENT_CRITUNDER },
     90 	{ ENVSYS_SWARNOVER, 	PENVSYS_EVENT_WARNOVER },
     91 	{ ENVSYS_SWARNUNDER,	PENVSYS_EVENT_WARNUNDER },
     92 	{ -1, 			-1 }
     93 };
     94 
     95 static struct workqueue *seewq;
     96 static struct callout seeco;
     97 static bool sme_events_initialized = false;
     98 kmutex_t sme_list_mtx, sme_event_mtx, sme_event_init_mtx;
     99 kcondvar_t sme_event_cv;
    100 
    101 /* 10 seconds of timeout for the callout */
    102 static int sme_events_timeout = 10;
    103 static int sme_events_timeout_sysctl(SYSCTLFN_PROTO);
    104 #define SME_EVTIMO 	(sme_events_timeout * hz)
    105 
    106 /*
    107  * sysctl(9) stuff to handle the refresh value in the callout
    108  * function.
    109  */
    110 static int
    111 sme_events_timeout_sysctl(SYSCTLFN_ARGS)
    112 {
    113 	struct sysctlnode node;
    114 	int timo, error;
    115 
    116 	node = *rnode;
    117 	timo = sme_events_timeout;
    118 	node.sysctl_data = &timo;
    119 
    120 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
    121 	if (error || newp == NULL)
    122 		return error;
    123 
    124 	/* min 1s */
    125 	if (timo < 1)
    126 		return EINVAL;
    127 
    128 	sme_events_timeout = timo;
    129 	return 0;
    130 }
    131 
    132 SYSCTL_SETUP(sysctl_kern_envsys_timeout_setup, "sysctl kern.envsys subtree")
    133 {
    134 	const struct sysctlnode *node, *envsys_node;
    135 
    136 	sysctl_createv(clog, 0, NULL, &node,
    137 			CTLFLAG_PERMANENT,
    138 			CTLTYPE_NODE, "kern", NULL,
    139 			NULL, 0, NULL, 0,
    140 			CTL_KERN, CTL_EOL);
    141 
    142 	sysctl_createv(clog, 0, &node, &envsys_node,
    143 			0,
    144 			CTLTYPE_NODE, "envsys", NULL,
    145 			NULL, 0, NULL, 0,
    146 			CTL_CREATE, CTL_EOL);
    147 
    148 	sysctl_createv(clog, 0, &envsys_node, &node,
    149 			CTLFLAG_READWRITE,
    150 			CTLTYPE_INT, "refresh_value",
    151 			SYSCTL_DESCR("wait time in seconds to refresh "
    152 			    "sensors being monitored"),
    153 			sme_events_timeout_sysctl, 0, &sme_events_timeout, 0,
    154 			CTL_CREATE, CTL_EOL);
    155 }
    156 
    157 /*
    158  * sme_event_register:
    159  *
    160  * 	+ Registers a new sysmon envsys event or updates any event
    161  * 	  already in the queue.
    162  */
    163 int
    164 sme_event_register(prop_dictionary_t sdict, envsys_data_t *edata,
    165 		   const char *drvn, const char *objkey,
    166 		   int32_t critval, int crittype, int powertype)
    167 {
    168 	sme_event_t *see = NULL;
    169 	prop_object_t obj;
    170 	bool critvalup = false;
    171 	int error = 0;
    172 
    173 	KASSERT(sdict != NULL || edata != NULL);
    174 
    175 	mutex_enter(&sme_event_mtx);
    176 	/*
    177 	 * check if the event is already on the list and return
    178 	 * EEXIST if value provided hasn't been changed.
    179 	 */
    180 	LIST_FOREACH(see, &sme_events_list, see_list) {
    181 		if (strcmp(edata->desc, see->pes.pes_sensname) == 0)
    182 			if (crittype == see->type) {
    183 				if (see->critval == critval) {
    184 					DPRINTF(("%s: dev=%s sensor=%s type=%d "
    185 				    	    "(already exists)\n", __func__,
    186 				    	    see->pes.pes_dvname,
    187 				    	    see->pes.pes_sensname, see->type));
    188 					mutex_exit(&sme_event_mtx);
    189 					return EEXIST;
    190 				}
    191 				critvalup = true;
    192 				break;
    193 			}
    194 	}
    195 
    196 	/*
    197 	 * Critical condition operation requested by userland.
    198 	 */
    199 	if (objkey && critval && critvalup) {
    200 		obj = prop_dictionary_get(sdict, objkey);
    201 		if (obj != NULL) {
    202 			/*
    203 			 * object is already in dictionary and value
    204 			 * provided is not the same than we have
    205 			 * currently,  update the critical value.
    206 			 */
    207 			see->critval = critval;
    208 			DPRINTF(("%s: sensor=%s type=%d (critval updated)\n",
    209 				 __func__, edata->desc, see->type));
    210 			error = sme_sensor_upint32(sdict, objkey, critval);
    211 			mutex_exit(&sme_event_mtx);
    212 			return error;
    213 		}
    214 	}
    215 
    216 	/*
    217 	 * The event is not in on the list or in a dictionary, create a new
    218 	 * sme event, assign required members and update the object in
    219 	 * the dictionary.
    220 	 */
    221 	see = NULL;
    222 	see = kmem_zalloc(sizeof(*see), KM_NOSLEEP);
    223 	if (see == NULL) {
    224 		mutex_exit(&sme_event_mtx);
    225 		return ENOMEM;
    226 	}
    227 
    228 	see->critval = critval;
    229 	see->type = crittype;
    230 	(void)strlcpy(see->pes.pes_dvname, drvn,
    231 	    sizeof(see->pes.pes_dvname));
    232 	see->pes.pes_type = powertype;
    233 	(void)strlcpy(see->pes.pes_sensname, edata->desc,
    234 	    sizeof(see->pes.pes_sensname));
    235 	see->snum = edata->sensor;
    236 
    237 	DPRINTF(("%s: registering dev=%s sensor=%s snum=%d type=%d "
    238 	    "critval=%" PRIu32 "\n", __func__,
    239 	    see->pes.pes_dvname, see->pes.pes_sensname,
    240 	    see->snum, see->type, see->critval));
    241 
    242 	LIST_INSERT_HEAD(&sme_events_list, see, see_list);
    243 	/*
    244 	 * Initialize the events framework if it wasn't initialized
    245 	 * before.
    246 	 */
    247 	mutex_enter(&sme_event_init_mtx);
    248 	mutex_exit(&sme_event_mtx);
    249 	if (sme_events_initialized == false)
    250 		error = sme_events_init();
    251 	mutex_exit(&sme_event_init_mtx);
    252 	if (error)
    253 		kmem_free(see, sizeof(*see));
    254 	return error;
    255 }
    256 
    257 /*
    258  * sme_event_unregister_all:
    259  *
    260  * 	+ Unregisters all sysmon envsys events associated with a
    261  * 	  sysmon envsys device.
    262  */
    263 void
    264 sme_event_unregister_all(const char *sme_name)
    265 {
    266 	sme_event_t *see;
    267 	int evcounter = 0;
    268 
    269 	KASSERT(sme_name != NULL);
    270 
    271 	mutex_enter(&sme_event_mtx);
    272 	LIST_FOREACH(see, &sme_events_list, see_list) {
    273 		if (strcmp(see->pes.pes_dvname, sme_name) == 0)
    274 			evcounter++;
    275 	}
    276 
    277 	DPRINTF(("%s: total events %d (%s)\n", __func__,
    278 	    evcounter, sme_name));
    279 
    280 	while ((see = LIST_FIRST(&sme_events_list)) != NULL) {
    281 		if (evcounter == 0)
    282 			break;
    283 
    284 		if (strcmp(see->pes.pes_dvname, sme_name) == 0) {
    285 			DPRINTF(("%s: event %s %d removed (%s)\n", __func__,
    286 			    see->pes.pes_sensname, see->type, sme_name));
    287 
    288 			while (see->see_flags & SME_EVENT_WORKING)
    289 				cv_wait(&sme_event_cv, &sme_event_mtx);
    290 
    291 			LIST_REMOVE(see, see_list);
    292 			kmem_free(see, sizeof(*see));
    293 			evcounter--;
    294 		}
    295 	}
    296 
    297 	if (LIST_EMPTY(&sme_events_list)) {
    298 		mutex_enter(&sme_event_init_mtx);
    299 		mutex_exit(&sme_event_mtx);
    300 		sme_events_destroy();
    301 		mutex_exit(&sme_event_init_mtx);
    302 		return;
    303 	}
    304 
    305 	mutex_exit(&sme_event_mtx);
    306 }
    307 
    308 /*
    309  * sme_event_unregister:
    310  *
    311  * 	+ Unregisters a sysmon envsys event.
    312  */
    313 int
    314 sme_event_unregister(const char *sensor, int type)
    315 {
    316 	sme_event_t *see;
    317 	bool found = false;
    318 
    319 	KASSERT(sensor != NULL);
    320 
    321 	mutex_enter(&sme_event_mtx);
    322 	LIST_FOREACH(see, &sme_events_list, see_list) {
    323 		if (strcmp(see->pes.pes_sensname, sensor) == 0) {
    324 			if (see->type == type) {
    325 				found = true;
    326 				break;
    327 			}
    328 		}
    329 	}
    330 
    331 	if (!found) {
    332 		mutex_exit(&sme_event_mtx);
    333 		return EINVAL;
    334 	}
    335 
    336 	while (see->see_flags & SME_EVENT_WORKING)
    337 		cv_wait(&sme_event_cv, &sme_event_mtx);
    338 
    339 	DPRINTF(("%s: removing dev=%s sensor=%s type=%d\n",
    340 	    __func__, see->pes.pes_dvname, sensor, type));
    341 	LIST_REMOVE(see, see_list);
    342 	/*
    343 	 * So the events list is empty, we'll do the following:
    344 	 *
    345 	 * 	- stop and destroy the callout.
    346 	 * 	- destroy the workqueue.
    347 	 */
    348 	if (LIST_EMPTY(&sme_events_list)) {
    349 		mutex_enter(&sme_event_init_mtx);
    350 		mutex_exit(&sme_event_mtx);
    351 		sme_events_destroy();
    352 		mutex_exit(&sme_event_init_mtx);
    353 		goto out;
    354 	}
    355 	mutex_exit(&sme_event_mtx);
    356 
    357 out:
    358 	kmem_free(see, sizeof(*see));
    359 	return 0;
    360 }
    361 
    362 /*
    363  * sme_event_drvadd:
    364  *
    365  * 	+ Adds a new sysmon envsys event for a driver if a sensor
    366  * 	  has set any accepted monitoring flag.
    367  */
    368 void
    369 sme_event_drvadd(void *arg)
    370 {
    371 	sme_event_drv_t *sed_t = arg;
    372 	int error = 0;
    373 
    374 	KASSERT(sed_t != NULL);
    375 
    376 #define SEE_REGEVENT(a, b, c)						\
    377 do {									\
    378 	if (sed_t->edata->flags & (a)) {				\
    379 		char str[32] = "monitoring-state-";			\
    380 									\
    381 		error = sme_event_register(sed_t->sdict,		\
    382 				      sed_t->edata,			\
    383 				      sed_t->sme->sme_name,		\
    384 				      NULL,				\
    385 				      0,				\
    386 				      (b),				\
    387 				      sed_t->powertype);		\
    388 		if (error && error != EEXIST)				\
    389 			printf("%s: failed to add event! "		\
    390 			    "error=%d sensor=%s event=%s\n",		\
    391 			    __func__, error, sed_t->edata->desc, (c));	\
    392 		else {							\
    393 			(void)strlcat(str, (c), sizeof(str));		\
    394 			mutex_enter(&sme_event_mtx);			\
    395 			prop_dictionary_set_bool(sed_t->sdict,		\
    396 						 str,			\
    397 						 true);			\
    398 			mutex_exit(&sme_event_mtx);			\
    399 		}							\
    400 	}								\
    401 } while (/* CONSTCOND */ 0)
    402 
    403 	SEE_REGEVENT(ENVSYS_FMONCRITICAL,
    404 		     PENVSYS_EVENT_CRITICAL,
    405 		     "critical");
    406 
    407 	SEE_REGEVENT(ENVSYS_FMONCRITUNDER,
    408 		     PENVSYS_EVENT_CRITUNDER,
    409 		     "critunder");
    410 
    411 	SEE_REGEVENT(ENVSYS_FMONCRITOVER,
    412 		     PENVSYS_EVENT_CRITOVER,
    413 		     "critover");
    414 
    415 	SEE_REGEVENT(ENVSYS_FMONWARNUNDER,
    416 		     PENVSYS_EVENT_WARNUNDER,
    417 		     "warnunder");
    418 
    419 	SEE_REGEVENT(ENVSYS_FMONWARNOVER,
    420 		     PENVSYS_EVENT_WARNOVER,
    421 		     "warnover");
    422 
    423 	SEE_REGEVENT(ENVSYS_FMONDRVSTATE,
    424 		     PENVSYS_EVENT_DRIVE_STCHANGED,
    425 		     "drvstchanged");
    426 
    427 	/* we are done, free memory now */
    428 	kmem_free(sed_t, sizeof(*sed_t));
    429 }
    430 
    431 /*
    432  * sme_events_init:
    433  *
    434  * 	+ Initializes the events framework.
    435  */
    436 int
    437 sme_events_init(void)
    438 {
    439 	int error;
    440 
    441 	KASSERT(mutex_owned(&sme_event_init_mtx));
    442 
    443 	error = workqueue_create(&seewq, "envsysev",
    444 	    sme_events_worker, NULL, 0, IPL_SOFTCLOCK, WQ_MPSAFE);
    445 	if (error)
    446 		goto out;
    447 
    448 	callout_init(&seeco, 0);
    449 	callout_setfunc(&seeco, sme_events_check, NULL);
    450 	callout_schedule(&seeco, SME_EVTIMO);
    451 	sme_events_initialized = true;
    452 	DPRINTF(("%s: events framework initialized\n", __func__));
    453 
    454 out:
    455 	return error;
    456 }
    457 
    458 /*
    459  * sme_events_destroy:
    460  *
    461  * 	+ Destroys the events framework: the workqueue and the
    462  * 	  callout are stopped and destroyed because there are not
    463  * 	  events in the queue.
    464  */
    465 void
    466 sme_events_destroy(void)
    467 {
    468 	KASSERT(mutex_owned(&sme_event_init_mtx));
    469 
    470 	callout_stop(&seeco);
    471 	sme_events_initialized = false;
    472 	DPRINTF(("%s: events framework destroyed\n", __func__));
    473 	callout_destroy(&seeco);
    474 	workqueue_destroy(seewq);
    475 }
    476 
    477 /*
    478  * sme_events_check:
    479  *
    480  * 	+ Runs the work on each sysmon envsys event in our
    481  * 	  workqueue periodically with callout.
    482  */
    483 void
    484 sme_events_check(void *arg)
    485 {
    486 	sme_event_t *see;
    487 
    488 	LIST_FOREACH(see, &sme_events_list, see_list) {
    489 		DPRINTFOBJ(("%s: dev=%s sensor=%s type=%d\n",
    490 		    __func__,
    491 		    see->pes.pes_dvname,
    492 		    see->pes.pes_sensname,
    493 		    see->type));
    494 		workqueue_enqueue(seewq, &see->see_wk, NULL);
    495 	}
    496 	callout_schedule(&seeco, SME_EVTIMO);
    497 }
    498 
    499 /*
    500  * sme_events_worker:
    501  *
    502  * 	+ workqueue thread that checks if there's a critical condition
    503  * 	  and sends an event if the condition was triggered.
    504  */
    505 void
    506 sme_events_worker(struct work *wk, void *arg)
    507 {
    508 	const struct sme_sensor_state *esds = sme_sensor_drive_state;
    509 	const struct sme_sensor_event *sse = sme_sensor_event;
    510 	sme_event_t *see = (void *)wk;
    511 	struct sysmon_envsys *sme;
    512 	envsys_data_t *edata;
    513 	int i, error = 0;
    514 
    515 	KASSERT(wk == &see->see_wk);
    516 
    517 	mutex_enter(&sme_event_mtx);
    518 	see->see_flags |= SME_EVENT_WORKING;
    519 
    520 	/*
    521 	 * We have to find the sme device by looking
    522 	 * at the power envsys device name.
    523 	 */
    524 	mutex_enter(&sme_list_mtx);
    525 	LIST_FOREACH(sme, &sysmon_envsys_list, sme_list)
    526 		if (strcmp(sme->sme_name, see->pes.pes_dvname) == 0)
    527 			break;
    528 	mutex_exit(&sme_list_mtx);
    529 
    530 	KASSERT(sme != NULL);
    531 
    532 	/* get the sensor with the index specified in see->snum */
    533 	edata = &sme->sme_sensor_data[see->snum];
    534 
    535 	/*
    536 	 * refresh the sensor that was marked with a critical
    537 	 * event.
    538 	 */
    539 	if ((sme->sme_flags & SME_DISABLE_GTREDATA) == 0) {
    540 		error = (*sme->sme_gtredata)(sme, edata);
    541 		if (error)
    542 			return;
    543 	}
    544 
    545 	DPRINTFOBJ(("%s: desc=%s sensor=%d units=%d value_cur=%d\n",
    546 	    __func__, edata->desc, edata->sensor,
    547 	    edata->units, edata->value_cur));
    548 
    549 #define SME_SEND_NORMALEVENT()						\
    550 do {									\
    551 	see->evsent = false;						\
    552 	sysmon_penvsys_event(&see->pes, PENVSYS_EVENT_NORMAL);		\
    553 } while (/* CONSTCOND */ 0)
    554 
    555 #define SME_SEND_EVENT(type)						\
    556 do {									\
    557 	see->evsent = true;						\
    558 	sysmon_penvsys_event(&see->pes, (type));			\
    559 } while (/* CONSTCOND */ 0)
    560 
    561 	switch (see->type) {
    562 	/*
    563 	 * if state is the same than the one that matches sse[i].state,
    564 	 * send the event...
    565 	 */
    566 	case PENVSYS_EVENT_CRITICAL:
    567 	case PENVSYS_EVENT_CRITUNDER:
    568 	case PENVSYS_EVENT_CRITOVER:
    569 	case PENVSYS_EVENT_WARNUNDER:
    570 	case PENVSYS_EVENT_WARNOVER:
    571 		for (i = 0; sse[i].state != -1; i++)
    572 			if (sse[i].event == see->type)
    573 				break;
    574 
    575 		if (see->evsent && edata->state == ENVSYS_SVALID)
    576 			SME_SEND_NORMALEVENT();
    577 
    578 		if (!see->evsent && edata->state == sse[i].state)
    579 			SME_SEND_EVENT(see->type);
    580 
    581 		break;
    582 	/*
    583 	 * if value_cur is lower than the limit, send the event...
    584 	 */
    585 	case PENVSYS_EVENT_BATT_USERCAP:
    586 	case PENVSYS_EVENT_USER_CRITMIN:
    587 		if (see->evsent && edata->value_cur > see->critval)
    588 			SME_SEND_NORMALEVENT();
    589 
    590 		if (!see->evsent && edata->value_cur < see->critval)
    591 			SME_SEND_EVENT(see->type);
    592 
    593 		break;
    594 	/*
    595 	 * if value_cur is higher than the limit, send the event...
    596 	 */
    597 	case PENVSYS_EVENT_USER_CRITMAX:
    598 		if (see->evsent && edata->value_cur < see->critval)
    599 			SME_SEND_NORMALEVENT();
    600 
    601 		if (!see->evsent && edata->value_cur > see->critval)
    602 			SME_SEND_EVENT(see->type);
    603 
    604 		break;
    605 	/*
    606 	 * if value_cur is not ENVSYS_DRIVE_ONLINE, send the event...
    607 	 */
    608 	case PENVSYS_EVENT_DRIVE_STCHANGED:
    609 		/* the state has not been changed, just ignore the event */
    610 		if (edata->value_cur == see->evsent)
    611 			break;
    612 
    613 		for (i = 0; esds[i].type != -1; i++)
    614 			if (esds[i].type == edata->value_cur)
    615 				break;
    616 
    617 		/* copy current state description  */
    618 		(void)strlcpy(see->pes.pes_statedesc, esds[i].desc,
    619 		    sizeof(see->pes.pes_statedesc));
    620 
    621 		/* state is ok again... send a normal event */
    622 		if (see->evsent && edata->value_cur == ENVSYS_DRIVE_ONLINE)
    623 			SME_SEND_NORMALEVENT();
    624 
    625 		/* something bad happened to the drive... send the event */
    626 		if (see->evsent || edata->value_cur != ENVSYS_DRIVE_ONLINE) {
    627 			/* save current drive state */
    628 			see->evsent = edata->value_cur;
    629 			sysmon_penvsys_event(&see->pes, see->type);
    630 		}
    631 
    632 		break;
    633 	}
    634 	see->see_flags &= ~SME_EVENT_WORKING;
    635 	cv_broadcast(&sme_event_cv);
    636 	mutex_exit(&sme_event_mtx);
    637 }
    638