linux

iv/linux

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Julian Wiedmann 1e4a382fdc s390/qdio: clear DSCI prior to scanning multiple input queues

For devices with multiple input queues, tiqdio_call_inq_handlers()
iterates over all input queues and clears the device's DSCI
during each iteration. If the DSCI is re-armed during one
of the later iterations, we therefore do not scan the previous
queues again.
The re-arming also raises a new adapter interrupt. But its
handler does not trigger a rescan for the device, as the DSCI
has already been erroneously cleared.
This can result in queue stalls on devices with multiple
input queues.

Fix it by clearing the DSCI just once, prior to scanning the queues.

As the code is moved in front of the loop, we also need to access
the DSCI directly (ie irq->dsci) instead of going via each queue's
parent pointer to the same irq. This is not a functional change,
and a follow-up patch will clean up the other users.

In practice, this bug only affects CQ-enabled HiperSockets devices,
ie. devices with sysfs-attribute "hsuid" set. Setting a hsuid is
needed for AF_IUCV socket applications that use HiperSockets
communication.

Fixes: 104ea556ee7f ("qdio: support asynchronous delivery of storage blocks")
Cc: <stable@vger.kernel.org> # v3.2+
Reviewed-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2017-02-03 13:50:19 +01:00

block

s390/dcssblk: fix device size calculation in dcssblk_direct_access()

2017-02-03 13:50:17 +01:00

char

s390: use false/true when using bool

2017-01-16 07:27:54 +01:00

cio

s390/qdio: clear DSCI prior to scanning multiple input queues

2017-02-03 13:50:19 +01:00

crypto

s390/zcrypt: use spin_lock_bh for all queue locks and unlocks.