lw2plus/fcal_leds/fcal_leds_thread.c

	fcal_leds_thread.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2001 by Sun Microsystems, Inc.
 * All rights reserved.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <stdarg.h>
#include <pthread.h>
#include <libintl.h>
#include <libdevinfo.h>
#include <syslog.h>
#include <sys/i2c/clients/i2c_client.h>
#include <poll.h>
#include "fcal_leds.h"

static char fcal_disk_unit[] = FCAL_PICL_DISK_UNIT;

static int update_picl(led_dtls_t *dtls, int disk);
static int get_drv_info(di_node_t node, led_dtls_t *dtls);
static int walk_disks(di_node_t node, led_dtls_t *dtls);
static int chk_minors(led_dtls_t *dtls);
static void set_led(int diskNo, token_t led_tok, led_dtls_t *dtls);
static int set_clr_led(int diskNo, token_t led_tok, led_dtls_t *dtls, int set);
void set_led(int diskNo, token_t led_tok, led_dtls_t *dtls);
void clr_led(int diskNo, token_t led_tok, led_dtls_t *dtls);
static void retry_led(led_dtls_t *dtls);
static void start_led_test(led_dtls_t *dtls, int disk);
static void end_led_test(led_dtls_t *dtls, int disk);
static int wait_a_while(void);

/*
 * variant of strerror() which guards against negative errno and null strings
 */
char *
mystrerror(int err)
{
    static char *unknown_errno = "unknown errno";
    char *ptr;

    if ((err < 0) || ((ptr = strerror(err)) == NULL)) {
        ptr = unknown_errno;
    }
    return (ptr);
}

void
delete_disk_unit(led_dtls_t *dtls, int disk)
{
    int         r;
    picl_nodehdl_t      slotndh;
    picl_nodehdl_t      diskndh;

    r = find_disk_slot(dtls, disk, &slotndh);
    if (r != PICL_SUCCESS)
        return;

    /*
     * is there a disk-unit node here?
     */
    r = ptree_find_node(slotndh, PICL_PROP_NAME,
        PICL_PTYPE_CHARSTRING, fcal_disk_unit,
        sizeof (fcal_disk_unit), &diskndh);
    if (r != PICL_SUCCESS)
        return;

    /*
     * remove disk-unit node and its properties
     */
    r = ptree_delete_node(diskndh);
    if (r != PICL_SUCCESS)
        return;
    (void) ptree_destroy_node(diskndh);
}

/*
 * update_picl
 * Called when disk goes off-line or goes to ready status.
 * In the case of disk ready, locate platform tree node for the disk
 * and add a target property (if missing).
 * (The target address is fixed for a given disk slot and is used to
 * tie the frutree disk-unit to the correct ssd node).
 * Returns EAGAIN for a retriable failure, otherwise 0.
 */
static int
update_picl(led_dtls_t *dtls, int disk)
{
    static char     trailer[] = ",0";
    picl_nodehdl_t      slotndh;
    picl_nodehdl_t      diskndh;
    ptree_propinfo_t    propinfo;
    int         r;

    if (dtls->disk_detected[disk] != 0) {
        picl_nodehdl_t      fpndh;
        picl_nodehdl_t      ssdndh;
        picl_prophdl_t      tbl_h;
        picl_prophdl_t      tbl_prop_h;
        picl_prophdl_t      row_props_h[FCAL_DEVTABLE_NCOLS];
        char            valbuf[80];
        char            addr[MAXPATHLEN];
        char            *ptrd;
        const uchar_t       *ptrs;
        int         len;
        int         addr_len;

        for (;;) {
            r = ptree_get_node_by_path(dtls->fcal_disk_parent,
                &fpndh);
            if (r != PICL_SUCCESS) {
                return (0);
            }
            r = ptree_get_propval_by_name(fpndh,
                PICL_PROP_CLASSNAME, (void *)valbuf,
                sizeof (valbuf));
            if (r != PICL_SUCCESS) {
                return (0);
            } else if (strcmp(valbuf, "fp") == 0) {
                /*
                 * The node with class fp (if present) is a
                 * holding node representing no actual hardware.
                 * Its presence results in two nodes with the
                 * same effective address. (The fp class node is
                 * UnitAddress 0,0 and the other fp node [class
                 * devctl] has bus-addr 0,0). Locating the
                 * required fp node for dynamic reconfiguration
                 * then goes wrong. So, just remove it.
                 */
                SYSLOG(LOG_WARNING, EM_SPURIOUS_FP);
                r = ptree_delete_node(fpndh);
                if (r == PICL_SUCCESS) {
                    (void) ptree_destroy_node(fpndh);
                    continue;
                }
                return (0);
            } else {
                break;
            }
        }
        /*
         * Got a good parent node. Look at its children for a node
         * with this new port name.
         *
         * generate expected bus-addr property from the port-wwn
         * Note: dtls->disk_port[disk] points to an array of uchar_t,
         * the first character contains the length of the residue.
         * The bus-addr property is formatted as follows:
         *  wabcdef0123456789,0
         * where the 16 hex-digits represent 8 bytes from disk_port[];
         */
        ptrs = dtls->disk_port[disk];
        if (ptrs == NULL)
            return (0);
        len = *ptrs++;
        ptrd = addr;
        *ptrd++ = 'w';
        for (r = 0; r < len; r++, ptrd += 2) {
            (void) snprintf(ptrd, MAXPATHLEN - (ptrd - addr),
                "%.2x", *ptrs++);
        }
        addr_len = 1 + strlcat(addr, trailer, MAXPATHLEN);
        if (addr_len > MAXPATHLEN)
            return (0);
        r = ptree_find_node(fpndh, FCAL_PICL_PROP_BUS_ADDR,
            PICL_PTYPE_CHARSTRING, addr, addr_len, &ssdndh);
        /*
         * If the disk node corresponding to the newly inserted disk
         * cannot be found in the platform tree, we have probably
         * got in too early - probably before it's up to speed. In
         * this case, the WWN gleaned from devinfo may also be wrong.
         * This case is worth retrying in later polls when it may
         * succeed, so return EAGAIN. All other failures are probably
         * terminal, so log a failure and quit.
         */
        if (r == PICL_NODENOTFOUND)
            return (EAGAIN);
        if (r != PICL_SUCCESS) {
            SYSLOG(LOG_ERR, EM_NO_FP_NODE, disk);
            return (0);
        }

        /*
         * Found platform entry for disk, add target prop
         */
        r = ptree_init_propinfo(&propinfo, PTREE_PROPINFO_VERSION,
            PICL_PTYPE_INT, PICL_READ, sizeof (int),
            FCAL_PICL_PROP_TARGET, NULL, NULL);
        if (r != PICL_SUCCESS)
            return (0);
        (void) ptree_create_and_add_prop(ssdndh, &propinfo, &disk,
            NULL);

        /*
         * Remove pre-existing disk-unit node and its
         * properties - maybe its reference property is
         * out-of-date.
         */
        delete_disk_unit(dtls, disk);

        /*
         * Add a disk-unit node in frutree
         */
        r = find_disk_slot(dtls, disk, &slotndh);
        if (r != PICL_SUCCESS)
            return (0);
        r = ptree_create_and_add_node(slotndh, fcal_disk_unit,
            PICL_CLASS_FRU, &diskndh);
        if (r != PICL_SUCCESS)
            return (0);
        r = create_Device_table(&tbl_h, &tbl_prop_h);
        if (r != PICL_SUCCESS)
            return (0);
        r = ptree_init_propinfo(&propinfo,
            PTREE_PROPINFO_VERSION, PICL_PTYPE_CHARSTRING,
            PICL_READ, sizeof (PICL_CLASS_BLOCK), PICL_PROP_CLASS,
            NULL, NULL);
        if (r != PICL_SUCCESS)
            return (0);
        r = ptree_create_prop(&propinfo, PICL_CLASS_BLOCK,
            &row_props_h[0]);
        if (r != PICL_SUCCESS)
            return (0);
        r = ptree_init_propinfo(&propinfo, PTREE_PROPINFO_VERSION,
            PICL_PTYPE_REFERENCE, PICL_READ, sizeof (picl_prophdl_t),
            FCAL_PICL_BLOCK_REF, NULL, NULL);
        if (r != PICL_SUCCESS)
            return (0);
        r = ptree_create_prop(&propinfo, &ssdndh, &row_props_h[1]);
        if (r != PICL_SUCCESS)
            return (0);
        r = ptree_add_row_to_table(tbl_h, FCAL_DEVTABLE_NCOLS,
            row_props_h);
        if (r != PICL_SUCCESS)
            return (0);
        (void) ptree_add_prop(diskndh, tbl_prop_h);
    } else {
        /*
         * disk gone, remove disk_unit fru from frutree
         */
        delete_disk_unit(dtls, disk);
    }
    return (0);
}

static int
get_drv_info(di_node_t node, led_dtls_t *dtls)
{
    int *target_data;
    uchar_t *port_data = NULL;
    di_minor_t min_node;
    int i, r;
    int t = -1;
    int *newStatus = malloc(dtls->n_disks * sizeof (int));
    if (newStatus == NULL)
        return (0);

    for (i = 0; i < dtls->n_disks; i++) {
        newStatus[i] = MINORS_UNKNOWN;
    }
    r = di_prop_lookup_ints(DDI_DEV_T_ANY, node, HW_PROP_TARGET,
        &target_data);
    for (i = 0; i < r; i++) {
        t = target_data[i];
        if ((t >= 0) && (t < dtls->n_disks)) {
            /* set no minors until we know */
            newStatus[t] = NO_MINORS;
            break;          /* go with this node */
        }
    }
    if ((t >= 0) && (t < dtls->n_disks)) {
        r = di_prop_lookup_bytes(
            DDI_DEV_T_ANY, node, HW_PROP_PORT, &port_data);
        /*
         * The first byte of the array dtls->disk_port[t] contains
         * the length of the residue. So 255 is the maximum length
         * which can be handled. Limit the property data to this.
         */
        if (r > 255) {
            r = 0;
        }
        if ((r > 0) && (port_data != NULL)) {
            if ((dtls->disk_port[t] != NULL) &&
                (*(dtls->disk_port[t]) != r)) {
                /*
                 * existing data is of different length,
                 * free it and malloc a fresh array.
                 */
                free(dtls->disk_port[t]);
                dtls->disk_port[t] = NULL;
            }
            if (dtls->disk_port[t] == NULL) {
                dtls->disk_port[t] = malloc(r + 1);
            }
            if (dtls->disk_port[t] != NULL) {
                *(dtls->disk_port[t]) = (uchar_t)r;
                (void) memcpy(dtls->disk_port[t] + 1,
                    port_data, r);
            }
        }
        min_node = di_minor_next(node, DI_MINOR_NIL);
        if (min_node != DI_MINOR_NIL) {
            /*
             * device has minor device node(s)
             */
            newStatus[t] = HAS_MINORS;  /* got minor(s) */
        }
    }
    /*
     * propagate attachment status and note changes
     * don't propagate to absent disks, otherwise we may not detect a
     * status change when they're replugged.
     */
    r = 0;
    for (i = 0; i < dtls->n_disks; i++) {
        if ((newStatus[i] != MINORS_UNKNOWN) &&
            dtls->disk_detected[i] &&
            (dtls->disk_ready[i] != newStatus[i])) {
            dtls->disk_ready[i] = newStatus[i];
            r = 1;
        }
    }
    free(newStatus);
    return (r);
}

/*
 * Nodes belonging to the configured driver (dtls->fcal_driver) are
 * located in the device tree. A check is applied that any node found has
 * a physical address beginning with the configured search string
 * (dtls->fcal_disk_parent). For each suitable node found, get_drv_info()
 * is called to determine if a change of status has occurred.
 * Returns 1 if any status has changed - else 0.
 */
static int
walk_disks(di_node_t node, led_dtls_t *dtls)
{
    static char *sl_platform_sl = "/platform/";
    int r = 0;
    int len;
    /* find "/platform/" */
    char *ptr = strstr(dtls->fcal_disk_parent, sl_platform_sl);

    if (ptr == NULL)
        return (0);
    /* skip over "/platform" */
    ptr += strlen(sl_platform_sl) - 1;
    len = strlen(ptr);

    for (node = di_drv_first_node(dtls->fcal_driver, node);
        node != DI_NODE_NIL;
        node = di_drv_next_node(node)) {
        char *dev_path = di_devfs_path(node);

        if (dev_path == NULL) {
            /* no memory, just hope things get better */
            continue;
        }
        if (memcmp(dev_path, ptr, len) != 0) {
            /*
             * path name doesn't start right, skip this one
             */
            free(dev_path);
            continue;
        }
        free(dev_path);
        if (get_drv_info(node, dtls) != 0) {
            r = 1;  /* change observed */
        }
    }

    return (r);
}

static int
chk_minors(led_dtls_t *dtls)
{
    /*
     * sets disk_ready flags for disks with minor devices (attached)
     * returns 1 if any flags have changed else 0
     */
    int err = 0;
    int r = 0;
    di_node_t tree = di_init("/", DINFOCPYALL);
    if (tree == DI_NODE_NIL) {
        err = errno;
        SYSLOG(LOG_ERR, EM_DI_INIT_FAIL, mystrerror(err));
    }
    if (err == 0)
        r = walk_disks(tree, dtls);
    if (tree != DI_NODE_NIL)
        di_fini(tree);
    return (r);
}

boolean_t
is_led_test(led_dtls_t *dtls)
{
    int disk;
    for (disk = 0; disk < dtls->n_disks; disk++) {
        if (dtls->led_test_end[disk] != 0)
            return (B_TRUE);
    }
    return (B_FALSE);
}

static int
set_clr_led(int diskNo, token_t led_tok, led_dtls_t *dtls, int set)
{
    int err, led, disk, led_bit;
    i2c_port_t port;
    int mask = 0;
    int fd = open(dtls->fcal_leds, O_RDWR);
    if (fd < 0)
        return (0);
    /*
     * generate a mask for all controlled LEDs
     */
    for (led = 0; led < FCAL_LED_CNT; led++) {
        for (disk = 0; disk < dtls->n_disks; disk++) {
            mask |= dtls->led_addr[led][disk];
        }
    }
    port.value = 0;
    port.direction = DIR_INPUT;
    port.dir_mask = (uint8_t)mask;
    /* read current light settings */
    err = ioctl(fd, I2C_GET_PORT, &port);
    if (err < 0) {
        (void) close(fd);
        return (EAGAIN);
    }
    mask = port.value;
    /*
     * get bit setting for led to be changed
     */
    led = led_tok - LED_PROPS_START - 1;
    led_bit = dtls->led_addr[led][diskNo];
    if (dtls->assert_led_on == 0) {
        if (set == 0)
            mask |= led_bit;
        else
            mask &= ~led_bit;
    } else {
        if (set == 0)
            mask &= ~led_bit;
        else
            mask |= led_bit;
    }

    /*
     * re-write the leds
     */
    port.value = (uint8_t)mask;
    err = ioctl(fd, I2C_SET_PORT, &port);
    (void) close(fd);
    if (err == 0)
        return (0);
    return (EAGAIN);
}

static void
set_led(int diskNo, token_t led_tok, led_dtls_t *dtls)
{
    if (set_clr_led(diskNo, led_tok, dtls, 1) != 0)
        dtls->led_retry = B_TRUE;
    dtls->led_state[led_tok - LED_PROPS_START - 1][diskNo] =
        ((dtls->led_test_end[diskNo] != 0) ?
        LED_STATE_TEST : LED_STATE_ON);
}

void
clr_led(int diskNo, token_t led_tok, led_dtls_t *dtls)
{
    if (set_clr_led(diskNo, led_tok, dtls, 0) != 0)
        dtls->led_retry = B_TRUE;
    dtls->led_state[led_tok - LED_PROPS_START - 1][diskNo] =
        LED_STATE_OFF;
}

/*
 * have another go at getting the leds in step with required values
 */
static void
retry_led(led_dtls_t *dtls)
{
    int     r = 0;
    int     onFlag;
    int     diskNo;
    int     ledNo;
    led_state_t state;

    for (diskNo = 0; diskNo < dtls->n_disks; diskNo++) {
        for (ledNo = 0; ledNo < FCAL_LED_CNT; ledNo++) {
            state = dtls->led_state[ledNo][diskNo];
            if ((state == LED_STATE_ON) ||
                (state == LED_STATE_TEST))
                onFlag = 1;
            else
                onFlag = 0;
            r |= set_clr_led(diskNo, LED_PROPS_START + 1 + ledNo,
                dtls, onFlag);
        }
    }

    dtls->led_retry = (r != 0);
}

static void
start_led_test(led_dtls_t *dtls, int disk)
{
    int         led_no;

    /*
     * if the poll thread has failed, can't do led test
     */
    if (!dtls->polling)
        return;

    /*
     * set test interval - doubles as flag for LED-test in progress
     */
    dtls->led_test_end[disk] = dtls->led_test_time;
    for (led_no = 1; led_no <= FCAL_LED_CNT; led_no++) {
        set_led(disk, LED_PROPS_START + led_no, dtls);
    }
}

static void
end_led_test(led_dtls_t *dtls, int disk)
{
    /*
     * There is a problem with a disk coming on-line.
     * All its leds are lit for 10 seconds to meet the led-test
     * requirement. The true state for the fault led can be determined
     * immediately, but determination of whether to light blue or green
     * requires a response from libdevinfo. Device reconfiguration logic
     * (likely to be active at this time) holds a long term
     * lock preventing devinfo calls from completing. Rather than
     * leave a contradictory led indication showing during this
     * period, it is better to anticipate the green led result
     * and correct it when the facts are known.
     */
    clr_led(disk, FCAL_REMOK_LED, dtls);
    clr_led(disk, FCAL_FAULT_LED, dtls);
    dtls->led_state[FCAL_READY_LED - LED_PROPS_START - 1][disk] =
        LED_STATE_ON;
}

/*
 * Evaluate required wait time and wait until that time or an event.
 * Returns 0 for a time-out, otherwise the pending event(s).
 * If the finish_now flag is becomes set, this routine acknowledges
 * the request and waits for it to go away,
 * i.e. no return while finish_now is set.
 */
static int
wait_a_while(void)
{
    int r;
    int events;
    boolean_t acksent = B_FALSE;

    do {
        r = pthread_mutex_lock(&g_mutex);
        if (r != 0) {
            SYSLOG(LOG_ERR, EM_MUTEX_FAIL, mystrerror(r));
            return (0);
        }
        if (g_finish_now && !acksent) {
            g_leds_thread_ack = B_TRUE;
            (void) pthread_cond_signal(&g_cv_ack);
            acksent = B_TRUE;
        }
        r = pthread_cond_wait(&g_cv, &g_mutex);
        if (r != 0) {
            SYSLOG(LOG_ERR, EM_CONDWAITFAIL, mystrerror(r));
            (void) pthread_mutex_unlock(&g_mutex);
            return (0);
        }
        /*
         * whilst under the mutex, take a local copy of the events
         * and clear those that we handle
         */
        events = g_event_flag & (FCAL_EV_POLL | FCAL_EV_CONFIG);
        g_event_flag ^= events;
        (void) pthread_mutex_unlock(&g_mutex);
    } while (g_finish_now);

    return (events);
}

/*ARGSUSED*/
void *
fcal_leds_thread(void *args)
{
    led_dtls_t *dtls = g_led_dtls;
    int c, v;
    int err = 0;
    int events = 0;
    int fd_bkplane;
    i2c_port_t port;
    int lastVal = I2C_IOCTL_INIT;
    int ws;
    int mask;

    /*
     * generate a mask for presence and fault status bits
     */
    mask = 0;
    for (c = 0; c < dtls->n_disks; c++) {
        mask |= dtls->presence[c];
        mask |= dtls->faults[c];
    }

    /*
     * enter poll loop
     */
    for (;;) {
        /*
         * see if a LED-test timer has expired
         */
        for (c = 0; c < dtls->n_disks; c++) {
            if (dtls->led_test_end[c] > 0) {
                if (!dtls->polling) {
                    /* poll thread failure, end led-test */
                    dtls->led_test_end[c] = 0;
                } else if ((events & FCAL_EV_POLL) != 0) {
                    dtls->led_test_end[c]--;
                }
                if (dtls->led_test_end[c] == 0) {
                    /*
                     * clear blue and amber leds
                     */
                    end_led_test(dtls, c);
                    /* treat any status as a change */
                    lastVal = I2C_IOCTL_INIT;
                }
            }
        }
        fd_bkplane = open(dtls->fcal_status, O_RDONLY);
        if (fd_bkplane < 0) {
            SYSLOG(LOG_ERR, EM_CANT_OPEN, dtls->fcal_status);
            err = errno;
            break;
        }
        port.value = 0;
        /*
         * the direction and dir_mask fields are ignored,
         * so one can only guess at their possible use
         */
        port.direction = DIR_INPUT;
        port.dir_mask = (uint8_t)mask;
        c = ioctl(fd_bkplane, I2C_GET_PORT, &port);
        if (c < 0) {
            err = errno;
            (void) close(fd_bkplane);

            if (lastVal != I2C_IOCTL_FAIL) {
                SYSLOG(LOG_ERR, EM_I2C_GET_PORT,
                    mystrerror(err));
                lastVal = I2C_IOCTL_FAIL;
                events |= FCAL_EV_CONFIG;
            }
        } else {
            (void) close(fd_bkplane);
            ws = port.value & mask;
        }

        if ((c == 0) && (ws != lastVal)) {
            events |= FCAL_EV_CONFIG;
            lastVal = ws;
            for (c = 0; c < dtls->n_disks; c++) {
                /*
                 * first get the value of the relevant
                 * presence bit (as 0 or 1)
                 */
                v = ((lastVal & dtls->presence[c]) != 0);

                /* hold previous presence value */
                ws = dtls->disk_detected[c];

                /*
                 * the disk is present if the backplane
                 * status bit for this disk is equal to the
                 * configured assert_presence value
                 */
                dtls->disk_detected[c] =
                    (v == dtls->assert_presence);
                /*
                 * Don't add disk-unit node here for
                 * newly arrived disks. While the led
                 * test is running (and beyond)
                 * libdevinfo is locked out and we
                 * can't get port or target info.
                 */
                if ((!ws) && dtls->disk_detected[c]) {
                    /*
                     * disk has just come on-line
                     */
                    start_led_test(dtls, c);
                }
                /*
                 * clear leds and ready status
                 * for disks which have been removed
                 */
                if (ws && (!dtls->disk_detected[c])) {
                    clr_led(c, FCAL_REMOK_LED, dtls);
                    clr_led(c, FCAL_FAULT_LED, dtls);
                    clr_led(c, FCAL_READY_LED, dtls);
                    dtls->disk_ready[c] = NO_MINORS;
                    dtls->disk_prev[c] = NO_MINORS;
                    v = update_picl(dtls, c);
                    /*
                     * set or clear retry flag
                     */
                    dtls->picl_retry[c] = (v == EAGAIN);
                }
                /*
                 * for present disks which are not doing a
                 * led test, adjust fault LED
                 */
                if ((dtls->led_test_end[c] != 0) ||
                    (!dtls->disk_detected[c]))
                    continue;
                v = ((lastVal & dtls->faults[c]) != 0);
                if (v == dtls->assert_fault)
                    set_led(c, FCAL_FAULT_LED, dtls);
                else
                    clr_led(c, FCAL_FAULT_LED, dtls);
            }
        }

        /*
         * For detected disks whose status has changed, choose between
         * ready and ok to remove.
         * libdevinfo can be locked out for the entire duration of a
         * disk spin-up. So it is best not to seek this info while
         * a led-test is in progress. Otherwise the leds can be stuck
         * on for about 40 seconds.
         * Note that chk_minors() returns 0 unless a status change
         * has occurred.
         */
        if (!is_led_test(dtls) && chk_minors(dtls) != 0) {
            events = FCAL_EV_CONFIG;
            for (c = 0; c < dtls->n_disks; c++) {
                if (!dtls->disk_detected[c])
                    continue;
                /*
                 * When disk_ready changes, disk_prev is set
                 * to its previous value. This allows the
                 * direction of the last transistion to be
                 * determined.
                 */
                if ((dtls->disk_prev[c] == HAS_MINORS) &&
                    (dtls->disk_ready[c] == NO_MINORS)) {
                    clr_led(c, FCAL_READY_LED, dtls);
                    set_led(c, FCAL_REMOK_LED, dtls);
                } else {
                    set_led(c, FCAL_READY_LED, dtls);
                    clr_led(c, FCAL_REMOK_LED, dtls);
                }
            }
        }
        /*
         * Update PICL (disk-unit) for newly attached disks
         * ** see note in header file for significance
         *    of disk_prev and disk_ready flags.
         */
        for (c = 0; c < dtls->n_disks; c++) {
            if ((dtls->disk_prev[c] == NO_MINORS) &&
                (dtls->disk_ready[c] == HAS_MINORS)) {
                dtls->disk_prev[c] = HAS_MINORS;
                v = update_picl(dtls, c);
                /*
                 * set or clear retry flag
                 */
                dtls->picl_retry[c] = (v == EAGAIN);
            }
        }
        if ((events & FCAL_EV_CONFIG) != 0) {
            /*
             * set fast polling
             */
            dtls->fast_poll_end = dtls->relax_time_ticks;
        }
        /*
         * if updating a led failed (e.g. I2C busy), try again
         */
        if (dtls->led_retry)
            retry_led(dtls);

        events = wait_a_while();

        /*
         * when picl is recycled, wait_a_while sleeps until the
         * init routine has been called again.
         * This is the moment when dtls may have become stale.
         */
        if (dtls != g_led_dtls) {
            dtls = g_led_dtls;
            lastVal = I2C_IOCTL_INIT;

            /*
             * re-generate the presence and fault status mask
             * in case the .conf file has changed
             */
            mask = 0;
            for (c = 0; c < dtls->n_disks; c++) {
                mask |= dtls->presence[c];
                mask |= dtls->faults[c];
            }
        }

        /*
         * count down relaxation time counter if a poll event
         */
        if ((events & FCAL_EV_POLL) != 0) {
            if (dtls->fast_poll_end > 0)
                dtls->fast_poll_end--;
        }

        /*
         * if updating PICL needs retrying, try it now
         */
        for (c = 0; c < dtls->n_disks; c++) {
            if (dtls->picl_retry[c]) {
                v = update_picl(dtls, c);
                dtls->picl_retry[c] = (v == EAGAIN);
            }
        }
    }

    return ((void *)err);
}