WITNESS is the culprit was Re: latest 8.1 hangs on xpt_config

[Daniel Braniss]

> That's hardly a solution or reason.
 
of course it's not, just that last successful boot had WITNESS configured,
and with the latest patches it hang, compiling without WITNESS allowed
the boot to proceed.

>                                      Still please try the patch (or fresh
> 8-STABLE with it), may be it tell more.
> 
according to my logs (i do some hulahups sync'ing via svn/hg which makes it
abit of a problem following versions :-) your patch seems to be all ready
in my kernel:
hg log ata_xpt.c -p
changeset:   2939:440362ab79cb
branch:      8
tag:         tip
parent:      2938:fc1c9d5f4b38
parent:      2937:846cb2242d34
user:        danny at cs.huji.ac.il
date:        Fri Jul 23 08:41:24 2010 +0300
summary:     -- merge from head --

diff -r fc1c9d5f4b38 -r 440362ab79cb sys/cam/ata/ata_xpt.c
--- a/sys/cam/ata/ata_xpt.c     Fri Jul 23 08:40:46 2010 +0300
+++ b/sys/cam/ata/ata_xpt.c     Fri Jul 23 08:41:24 2010 +0300
@@ -134,6 +134,7 @@
        uint32_t        pm_prv;
        int             restart;
        int             spinup;
+       int             faults;
        u_int           caps;
        struct cam_periph *periph;
 } probe_softc;
@@ -738,14 +739,28 @@
        ident_buf = &path->device->ident_data;
 
        if ((done_ccb->ccb_h.status & CAM_STATUS_MASK) != CAM_REQ_CMP) {
-device_fail:   if ((!softc->restart) &&
-                   cam_periph_error(done_ccb, 0, 0, NULL) == ERESTART) {
+               if (softc->restart) {
+                       if (bootverbose) {
+                               cam_error_print(done_ccb,
+                                   CAM_ESF_ALL, CAM_EPF_ALL);
+                       }
+               } else if (cam_periph_error(done_ccb, 0, 0, NULL) == ERESTART)
                        return;
-               } else if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
+               if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0) {
                        /* Don't wedge the queue */
                        xpt_release_devq(done_ccb->ccb_h.path, /*count*/1,
                                         /*run_queue*/TRUE);
                }
+               if (softc->restart) {
+                       softc->faults++;
+                       if ((done_ccb->ccb_h.status & CAM_STATUS_MASK) ==
+                           CAM_CMD_TIMEOUT)
+                               softc->faults += 4;
+                       if (softc->faults < 10)
+                               goto done;
+                       else
+                               softc->restart = 0;
+               } else
                /* Old PIO2 devices may not support mode setting. */
                if (softc->action == PROBE_SETMODE &&
                    ata_max_pmode(ident_buf) <= ATA_PIO2 &&
@@ -761,7 +776,7 @@
                 * already marked unconfigured, notify the peripheral
                 * drivers that this device is no more.
                 */
-               if ((path->device->flags & CAM_DEV_UNCONFIGURED) == 0)
+device_fail:   if ((path->device->flags & CAM_DEV_UNCONFIGURED) == 0)
                        xpt_async(AC_LOST_DEVICE, path, NULL);
                found = 0;
                goto done;
@@ -1209,6 +1224,12 @@
                    !(work_ccb->cpi.hba_misc & PIM_NOBUSRESET) &&
                    !timevalisset(&request_ccb->ccb_h.path->bus->last_reset)) {
                        reset_ccb = xpt_alloc_ccb_nowait();
+                       if (reset_ccb == NULL) {
+                               request_ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
+                               xpt_free_ccb(work_ccb);
+                               xpt_done(request_ccb);
+                               return;
+                       }
                        xpt_setup_ccb(&reset_ccb->ccb_h, request_ccb->
ccb_h.path,
                              CAM_PRIORITY_NONE);
                        reset_ccb->ccb_h.func_code = XPT_RESET_BUS;
@@ -1228,6 +1249,7 @@
                    malloc(sizeof(ata_scan_bus_info), M_CAMXPT, M_NOWAIT);
                if (scan_info == NULL) {
                        request_ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
+                       xpt_free_ccb(work_ccb);
                        xpt_done(request_ccb);
                        return;
                }

cheers,
	danny