* chp_update_desc - update channel-path description
  * @chp - channel-path
  *
- * Update the channel-path description of the specified channel-path.
+ * Update the channel-path description of the specified channel-path
+ * including channel measurement related information.
  * Return zero on success, non-zero otherwise.
  */
 int chp_update_desc(struct channel_path *chp)
                return rc;
 
        rc = chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1);
+       if (rc)
+               return rc;
 
-       return rc;
+       return chsc_get_channel_measurement_chars(chp);
 }
 
 /**
                ret = -ENODEV;
                goto out_free;
        }
-
-       ret = chsc_get_channel_measurement_chars(chp);
-       if (ret)
-               goto out_free;
-
        dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id);
 
        /* make it known to the system */
 
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/device.h>
+#include <linux/mutex.h>
 #include <linux/pci.h>
 
 #include <asm/cio.h>
 
 void chsc_chp_offline(struct chp_id chpid)
 {
-       char dbf_txt[15];
+       struct channel_path *chp = chpid_to_chp(chpid);
        struct chp_link link;
+       char dbf_txt[15];
 
        sprintf(dbf_txt, "chpr%x.%02x", chpid.cssid, chpid.id);
        CIO_TRACE_EVENT(2, dbf_txt);
        link.chpid = chpid;
        /* Wait until previous actions have settled. */
        css_wait_for_slow_path();
+
+       mutex_lock(&chp->lock);
+       chp_update_desc(chp);
+       mutex_unlock(&chp->lock);
+
        for_each_subchannel_staged(s390_subchannel_remove_chpid, NULL, &link);
 }
 
 
 void chsc_chp_online(struct chp_id chpid)
 {
-       char dbf_txt[15];
+       struct channel_path *chp = chpid_to_chp(chpid);
        struct chp_link link;
+       char dbf_txt[15];
 
        sprintf(dbf_txt, "cadd%x.%02x", chpid.cssid, chpid.id);
        CIO_TRACE_EVENT(2, dbf_txt);
                link.chpid = chpid;
                /* Wait until previous actions have settled. */
                css_wait_for_slow_path();
+
+               mutex_lock(&chp->lock);
+               chp_update_desc(chp);
+               mutex_unlock(&chp->lock);
+
                for_each_subchannel_staged(__s390_process_res_acc, NULL,
                                           &link);
                css_schedule_reprobe();