s390/sclp: reduce dependency on event type masks

The event type masks can change asynchronously. These changes are reported
by SCLP to the OS by state-change events which are retrieved with the read
event data command. The SCLP driver has a request queue, there is a window
where the read event data request has not completed yet but the SCLP console
drivers are trying to queue output requests. As the masks are not updated
yet the requests are discarded.

The simplest fix is to queue the console requests independent of the
event type masks and rely on SCLP to return with an error code if a
specific event type is not available.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

3 files changed, 5 insertions, 14 deletions

diff --git a/drivers/s390/char/sclp_early.c b/drivers/s390/char/sclp_early.c
index 1918d9dff45d..5bd6cb145a87 100644
--- a/drivers/s390/char/sclp_early.c
+++ b/drivers/s390/char/sclp_early.c
@@ -281,7 +281,7 @@ out:
 
 static unsigned int __init sclp_con_check_linemode(struct init_sccb *sccb)
 {
-	if (!(sccb->sclp_send_mask & (EVTYP_OPCMD_MASK | EVTYP_PMSGCMD_MASK)))
+	if (!(sccb->sclp_send_mask & EVTYP_OPCMD_MASK))
 		return 0;
 	if (!(sccb->sclp_receive_mask & (EVTYP_MSG_MASK | EVTYP_PMSGCMD_MASK)))
 		return 0;
diff --git a/drivers/s390/char/sclp_rw.c b/drivers/s390/char/sclp_rw.c
index 3b13d58fe87b..35a84af875ee 100644
--- a/drivers/s390/char/sclp_rw.c
+++ b/drivers/s390/char/sclp_rw.c
@@ -33,7 +33,7 @@ static void sclp_rw_pm_event(struct sclp_register *reg,
 
 /* Event type structure for write message and write priority message */
 static struct sclp_register sclp_rw_event = {
-	.send_mask = EVTYP_MSG_MASK | EVTYP_PMSGCMD_MASK,
+	.send_mask = EVTYP_MSG_MASK,
 	.pm_event_fn = sclp_rw_pm_event,
 };
 
@@ -456,14 +456,9 @@ sclp_emit_buffer(struct sclp_buffer *buffer,
 		return -EIO;
 
 	sccb = buffer->sccb;
-	if (sclp_rw_event.sclp_receive_mask & EVTYP_MSG_MASK)
-		/* Use normal write message */
-		sccb->msg_buf.header.type = EVTYP_MSG;
-	else if (sclp_rw_event.sclp_receive_mask & EVTYP_PMSGCMD_MASK)
-		/* Use write priority message */
-		sccb->msg_buf.header.type = EVTYP_PMSGCMD;
-	else
-		return -EOPNOTSUPP;
+	/* Use normal write message */
+	sccb->msg_buf.header.type = EVTYP_MSG;
+
 	buffer->request.command = SCLP_CMDW_WRITE_EVENT_DATA;
 	buffer->request.status = SCLP_REQ_FILLED;
 	buffer->request.callback = sclp_writedata_callback;
diff --git a/drivers/s390/char/sclp_vt220.c b/drivers/s390/char/sclp_vt220.c
index b9a9f721716d..ae67386c03d3 100644
--- a/drivers/s390/char/sclp_vt220.c
+++ b/drivers/s390/char/sclp_vt220.c
@@ -206,10 +206,6 @@ sclp_vt220_callback(struct sclp_req *request, void *data)
 static int
 __sclp_vt220_emit(struct sclp_vt220_request *request)
 {
-	if (!(sclp_vt220_register.sclp_receive_mask & EVTYP_VT220MSG_MASK)) {
-		request->sclp_req.status = SCLP_REQ_FAILED;
-		return -EIO;
-	}
 	request->sclp_req.command = SCLP_CMDW_WRITE_EVENT_DATA;
 	request->sclp_req.status = SCLP_REQ_FILLED;
 	request->sclp_req.callback = sclp_vt220_callback;