From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-2.mimecast.com ([205.139.110.61]:58694 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727670AbfLBSQM (ORCPT ); Mon, 2 Dec 2019 13:16:12 -0500 Date: Mon, 2 Dec 2019 19:15:41 +0100 From: Cornelia Huck Subject: Re: [kvm-unit-tests PATCH v2 6/9] s390x: css: stsch, enumeration test Message-ID: <20191202191541.1ffd987e.cohuck@redhat.com> In-Reply-To: References: <1574945167-29677-1-git-send-email-pmorel@linux.ibm.com> <1574945167-29677-7-git-send-email-pmorel@linux.ibm.com> <20191202152246.4d627b0e.cohuck@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Pierre Morel Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, frankja@linux.ibm.com, david@redhat.com, thuth@redhat.com On Mon, 2 Dec 2019 18:53:16 +0100 Pierre Morel wrote: > On 2019-12-02 15:22, Cornelia Huck wrote: > > On Thu, 28 Nov 2019 13:46:04 +0100 > > Pierre Morel wrote: > >> +static int test_device_sid; > >> + > >> +static void test_enumerate(void) > >> +{ > >> + struct pmcw *pmcw = &schib.pmcw; > >> + int sid; > >> + int ret, i; > >> + int found = 0; > >> + > >> + for (sid = 0; sid < 0xffff; sid++) { > >> + ret = stsch(sid|SID_ONE, &schib); > > > > This seems a bit odd. You are basically putting the subchannel number > > into sid, OR in the one, and then use the resulting value as the sid > > (subchannel identifier). > > > >> + if (!ret && (pmcw->flags & PMCW_DNV)) { > >> + report_info("SID %04x Type %s PIM %x", sid, > > > > That's not a sid, but the subchannel number (see above). > > > >> + Channel_type[pmcw->st], pmcw->pim); > >> + for (i = 0; i < 8; i++) { > >> + if ((pmcw->pim << i) & 0x80) { > >> + report_info("CHPID[%d]: %02x", i, > >> + pmcw->chpid[i]); > >> + break; > >> + } > >> + } > >> + found++; > >> + > >> + } > > > > Here, you iterate over the 0-0xffff range, even if you got a condition > > code 3 (indicating no more subchannels in that set). Is that > > intentional? > > I thought there could be more subchannels. > I need then a break in the loop when this happens. > I will reread the PoP to see how to find that no more subchannel are in > that set. The fact that cc 3 for stsch == no more subchannels is unfortunately a bit scattered across the PoP :/ Dug it out some time ago, maybe it's still in the archives somewhere... > > > > >> + if (found && !test_device_sid) > >> + test_device_sid = sid|SID_ONE; > > > > You set test_device_sid to the last valid subchannel? Why? > > The last ? I wanted the first one It is indeed the first one, -ENOCOFFEE. > > I wanted something easy but I should have explain. > > To avoid doing complicated things like doing a sense on each valid > subchannel I just take the first one. > Should be enough as we do not go to the device in this test. Yes; but you plan to reuse that code, don't you? > > > > >> + } > >> + if (!found) { > >> + report("Found %d devices", 0, found); Now that I look at this again: If you got here, you always found 0 devices, so that message is not super helpful :) > >> + return; > >> + } > >> + ret = stsch(test_device_sid, &schib); > > > > Why do you do a stsch() again? > > right, no need. > In an internal version I used to print some informations from the SCHIB. > Since in between I overwrote the SHIB, I did it again. > But in this version; no need. You could copy the schib of the subchannel to be tested to a different place, but I'm not sure it's worth it. > > > > >> + if (ret) { > >> + report("Err %d on stsch on sid %08x", 0, ret, test_device_sid); > >> + return; > >> + } > >> + report("Tested", 1); > >> + return; > > > > I don't think you need this return statement. > > right I have enough work. :) > > > > > Your test only enumerates devices in the first subchannel set. Do you > > plan to enhance the test to enable the MSS facility and iterate over > > all subchannel sets? > > Yes, it is something we can do in a following series Sure, just asked out of interest :)