Added missing Xen Kernel Patches which were not commited because

[people/pmueller/ipfire-2.x.git] / src / patches / suse-2.6.27.31 / patches.arch / s390-08-01-cio-fix-mp-mode.diff

diff --git a/src/patches/suse-2.6.27.31/patches.arch/s390-08-01-cio-fix-mp-mode.diff b/src/patches/suse-2.6.27.31/patches.arch/s390-08-01-cio-fix-mp-mode.diff
new file mode 100644 (file)
index 0000000..852e22b
--- /dev/null
+++ b/src/patches/suse-2.6.27.31/patches.arch/s390-08-01-cio-fix-mp-mode.diff
@@ -0,0 +1,61 @@
+From: Gerald Schaefer <geraldsc@de.ibm.com>
+Subject: cio: fix subchannel multipath mode setup
+References: bnc#466462,LTC#51047
+
+Symptom:     Undefined behavior when trying to access DASD devices with more
+             than one CHPID: e.g. I/O errors due to timeouts after missing
+             interrupts, slow access to DASDs because single path mode is used.
+Problem:     Setup of subchannel multipath mode is not performed correctly
+             because changes to a local buffer are lost before they are sent
+             to the channel subsystem. In this state, the control unit assumes
+             multipath mode while the channel subsystem expects single path
+             mode. As a result, interrupts may not be correctly recognized
+             which leads to timeout situations and eventually I/O errors.
+             Also single path processing may slow down DASD access.
+Solution:    Apply changes to the subchannel configuration after modifying
+             the local buffer.
+
+Acked-by: John Jolly <jjolly@suse.de>
+
+---
+ drivers/s390/cio/device.c     |    6 ++++++
+ drivers/s390/cio/device_fsm.c |    2 ++
+ 2 files changed, 8 insertions(+)
+
+Index: linux-sles11/drivers/s390/cio/device.c
+===================================================================
+--- linux-sles11.orig/drivers/s390/cio/device.c
++++ linux-sles11/drivers/s390/cio/device.c
+@@ -1246,6 +1246,9 @@ static int io_subchannel_probe(struct su
+               return 0;
+       }
+       io_subchannel_init_fields(sch);
++      rc = cio_modify(sch);
++      if (rc)
++              goto out_schedule;
+       /*
+        * First check if a fitting device may be found amongst the
+        * disconnected devices or in the orphanage.
+@@ -1676,6 +1679,9 @@ static int ccw_device_console_enable(str
+       sch->private = cio_get_console_priv();
+       memset(sch->private, 0, sizeof(struct io_subchannel_private));
+       io_subchannel_init_fields(sch);
++      rc = cio_modify(sch);
++      if (rc)
++              return rc;
+       sch->driver = &io_subchannel_driver;
+       /* Initialize the ccw_device structure. */
+       cdev->dev.parent= &sch->dev;
+Index: linux-sles11/drivers/s390/cio/device_fsm.c
+===================================================================
+--- linux-sles11.orig/drivers/s390/cio/device_fsm.c
++++ linux-sles11/drivers/s390/cio/device_fsm.c
+@@ -1028,6 +1028,8 @@ void ccw_device_trigger_reprobe(struct c
+       sch->schib.pmcw.ena = 0;
+       if ((sch->lpm & (sch->lpm - 1)) != 0)
+               sch->schib.pmcw.mp = 1;
++      if (cio_modify(sch))
++              return;
+       /* We should also udate ssd info, but this has to wait. */
+       /* Check if this is another device which appeared on the same sch. */
+       if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {