Commit f276730f authored Aug 22, 2007 by Klaus D. Wacker Committed by Martin Schwidefsky Aug 22, 2007

[S390] qdio: fix EQBS handling on CCQ96



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 <kdwacker@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

parent 23eb68c5

drivers/s390/cio/qdio.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -195,6 +195,8 @@ qdio_do_eqbs(struct qdio_q q, unsigned char state,
		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;

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