From: Klaus D. Wacker QDIO returned from EQBS instruction in any case after return code CCQ=96 was issued regardless whether buffer states for at least one buffer were extracted or not. This caused FCP devices to hang when running under z/VM and having QIOASSASIST=ON and having high I/O rates. In order to fix this qdio return code processing of EQBS instruction after CCQ=96 is changed that buffers are returned and if no buffers where extracted the instruction is repeated at once. Signed-off-by: Klaus D. Wacker Signed-off-by: Martin Schwidefsky Signed-off-by: Heiko Carstens --- drivers/s390/cio/qdio.c | 2 ++ 1 file changed, 2 insertions(+) Index: quilt-2.6/drivers/s390/cio/qdio.c =================================================================== --- quilt-2.6.orig/drivers/s390/cio/qdio.c +++ quilt-2.6/drivers/s390/cio/qdio.c @@ -195,6 +195,8 @@ qdio_do_eqbs(struct qdio_q *q, unsigned again: ccq = do_eqbs(irq->sch_token, state, q_no, start, cnt); rc = qdio_check_ccq(q, ccq); + if ((ccq == 96) && (tmp_cnt != *cnt)) + rc = 0; if (rc == 1) { QDIO_DBF_TEXT5(1,trace,"eqAGAIN"); goto again; -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/