s390/qdio: don't touch the dsci in tiqdio_add_input_queues()

commit ac6639cd3db607d386616487902b4cc1850a7be5 upstream.

Current code sets the dsci to 0x00000080. Which doesn't make any sense,
as the indicator area is located in the _left-most_ byte.

Worse: if the dsci is the _shared_ indicator, this potentially clears
the indication of activity for a _different_ device.
tiqdio_thinint_handler() will then have no reason to call that device's
IRQ handler, and the device ends up stalling.

Fixes: d0c9d4a89f ("[S390] qdio: set correct bit in dsci")
Cc: <stable@vger.kernel.org>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Julian Wiedmann 2019-06-18 13:12:20 +02:00 committed by Greg Kroah-Hartman
parent ff5e6f2e74
commit 970871c643

View file

@ -80,7 +80,6 @@ void tiqdio_add_input_queues(struct qdio_irq *irq_ptr)
mutex_lock(&tiq_list_lock);
list_add_rcu(&irq_ptr->input_qs[0]->entry, &tiq_list);
mutex_unlock(&tiq_list_lock);
xchg(irq_ptr->dsci, 1 << 7);
}
void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr)