Re: [patch 16/17] s390: multiple subchannel sets support.

[Cornelia Huck <cornelia.huck@de.ibm.com>]

On Sat, 25 Feb 2006 06:12:02 -0500
Greg Smith <gsmith@nc.rr.com> wrote:

> However, __init_channel_subsystem does not recognize the -EIO return
> code from css_alloc_subchannel.

Good catch.

> I have verified that on a real machine that does not support multiple
> channel sets (a 9672) the CHSC_SDA_OC_MSS chsc request gets response
> code 0x0002.  The emulator also sets the response code to 0x0002.

The architecture seems to disagree somewhat :) (and I also got a
different response code on the non-MSS capable HW I tested on). On
further looking at the code, the check leaves room for improvement
anyway... I'd prefer the following patch:


s390: Improve response code handling in chsc_enable_facility().

Rather than checking for some known failures, check positively for the
success response code 0x0001 and return -EIO for unrecognized failure
response codes.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

 chsc.c |    5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index 8cf9905..f4183d6 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -1115,6 +1115,9 @@ chsc_enable_facility(int operation_code)
 		goto out;
 	}
 	switch (sda_area->response.code) {
+	case 0x0001: /* everything ok */
+		ret = 0;
+		break;
 	case 0x0003: /* invalid request block */
 	case 0x0007:
 		ret = -EINVAL;
@@ -1123,6 +1126,8 @@ chsc_enable_facility(int operation_code)
 	case 0x0101: /* facility not provided */
 		ret = -EOPNOTSUPP;
 		break;
+	default: /* something went wrong */
+		ret = -EIO;
 	}
  out:
 	free_page((unsigned long)sda_area);