s390/sclp: Suppress unnecessary Store Data warning

On systems that do not support Store Data events (such as when running
as KVM guest) the following warning message appears during boot:

 sclp_sd: Store Data request failed (eq=2, di=3, response=0x40f0,
          flags=0x00, status=0, rc=-5)

This warning does not add any useful information since the result is
expected due to missing support for that event type.

Suppress this message by checking the associated masks of supported
events before issuing a Store Data event.

Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

diff --git a/drivers/s390/char/sclp_sd.c b/drivers/s390/char/sclp_sd.c
index f9e164be7568f2c877609d1a487ab1d2ff6279b6..5aeb7e094a1cb935dc71ee2e4f7f380f70441a3c 100644 (file)
--- a/drivers/s390/char/sclp_sd.c
+++ b/drivers/s390/char/sclp_sd.c
@@ -194,6 +194,10 @@ static int sclp_sd_sync(unsigned long page, u8 eq, u8 di, u64 sat, u64 sa,
        struct sclp_sd_evbuf *evbuf;
        int rc;
 
+       if (!sclp_sd_register.sclp_send_mask ||
+           !sclp_sd_register.sclp_receive_mask)
+               return -EIO;
+
        sclp_sd_listener_init(&listener, __pa(sccb));
        sclp_sd_listener_add(&listener);