src/patches/suse-2.6.27.25/patches.arch/s390-09-01-cio_disable_notoper.patch

   1 From: Gerald Schaefer <geraldsc@de.ibm.com>
   2 Subject: cio: Properly disable not operational subchannel.
   3 References: bnc#477666,LTC#51619
   4
   5 Symptom:     Kernel BUG at drivers/s390/cio/device_fsm.c:1241!
   6 Problem:     After deferred cc=3 was received on all paths, a
   7              device was set to not operational to prepare for
   8              re-evaluation. An unsolicited interrupt indicating
   9              that the device became accessible again triggered
  10              an invalid event in the state machine (interrupt in
  11              not operational state).
  12 Solution:    Properly disable the subchannel before setting the
  13              device not operational. To be able to disable the
  14              subchannel reliably, pending status needs to be
  15              collected.
  16
  17 Acked-by: John Jolly <jjolly@suse.de>
  18
  19 ---
  20  drivers/s390/cio/cio.c        |   19 +++++--------------
  21  drivers/s390/cio/device_fsm.c |    4 ++--
  22  2 files changed, 7 insertions(+), 16 deletions(-)
  23
  24 Index: linux-sles11/drivers/s390/cio/device_fsm.c
  25 ===================================================================
  26 --- linux-sles11.orig/drivers/s390/cio/device_fsm.c
  27 +++ linux-sles11/drivers/s390/cio/device_fsm.c
  28 @@ -726,7 +726,7 @@ static void ccw_device_generic_notoper(s
  29  {
  30         struct subchannel *sch;
  31
  32 -       cdev->private->state = DEV_STATE_NOT_OPER;
  33 +       ccw_device_set_notoper(cdev);
  34         sch = to_subchannel(cdev->dev.parent);
  35         css_schedule_eval(sch->schid);
  36  }
  37 @@ -1048,7 +1048,7 @@ ccw_device_offline_irq(struct ccw_device
  38         sch = to_subchannel(cdev->dev.parent);
  39         /*
  40          * An interrupt in state offline means a previous disable was not
  41 -        * successful. Try again.
  42 +        * successful - should not happen, but we try to disable again.
  43          */
  44         cio_disable_subchannel(sch);
  45  }
  46 Index: linux-sles11/drivers/s390/cio/cio.c
  47 ===================================================================
  48 --- linux-sles11.orig/drivers/s390/cio/cio.c
  49 +++ linux-sles11/drivers/s390/cio/cio.c
  50 @@ -464,25 +464,16 @@ int cio_disable_subchannel(struct subcha
  51         if (ccode == 3)         /* Not operational. */
  52                 return -ENODEV;
  53
  54 -       if (scsw_actl(&sch->schib.scsw) != 0)
  55 -               /*
  56 -                * the disable function must not be called while there are
  57 -                *  requests pending for completion !
  58 -                */
  59 -               return -EBUSY;
  60 -
  61         for (retry = 5, ret = 0; retry > 0; retry--) {
  62                 sch->schib.pmcw.ena = 0;
  63                 ret = cio_modify(sch);
  64                 if (ret == -ENODEV)
  65                         break;
  66 -               if (ret == -EBUSY)
  67 -                       /*
  68 -                        * The subchannel is busy or status pending.
  69 -                        * We'll disable when the next interrupt was delivered
  70 -                        * via the state machine.
  71 -                        */
  72 -                       break;
  73 +               if (ret == -EBUSY) {
  74 +                       struct irb irb;
  75 +                       if (tsch(sch->schid, &irb) != 0)
  76 +                               break;
  77 +               }
  78                 if (ret == 0) {
  79                         stsch (sch->schid, &sch->schib);
  80                         if (!sch->schib.pmcw.ena)