From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1A36FC433DF for ; Tue, 11 Aug 2020 07:03:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DBC862078E for ; Tue, 11 Aug 2020 07:03:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="P1AWeZiE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728177AbgHKHDn (ORCPT ); Tue, 11 Aug 2020 03:03:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38752 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726792AbgHKHDm (ORCPT ); Tue, 11 Aug 2020 03:03:42 -0400 Received: from mail-oi1-x236.google.com (mail-oi1-x236.google.com [IPv6:2607:f8b0:4864:20::236]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6A43FC06174A for ; Tue, 11 Aug 2020 00:03:42 -0700 (PDT) Received: by mail-oi1-x236.google.com with SMTP id u24so11306146oiv.7 for ; Tue, 11 Aug 2020 00:03:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=from:references:in-reply-to:mime-version:thread-index:date :message-id:subject:to:cc; bh=MlFkUroiC5cUzWMMBz6G7bs43pc0dCCdF/xysr3+kGI=; b=P1AWeZiELJeMHdkeyXxKCZDXtaKlflQPgnF8XISkjtKPd0rgCcQssdbNJEsufuM7jw r4X3V3f/D0hlUr3gjMjlcZcGM8LIyF10jVakP+E3lbp6EvkHrqlnBMAmSMlXOadmQkDv fZ7D5Nu3/X+praqU/f5ZuIiDor9HJ3yAr1+OE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:references:in-reply-to:mime-version :thread-index:date:message-id:subject:to:cc; bh=MlFkUroiC5cUzWMMBz6G7bs43pc0dCCdF/xysr3+kGI=; b=djVl+Jgowbqgvo3yDXh+0lzGr/WmIkx+fpJXwHs1E5QwpYG92vbGesWSY08vGK2h2n GXHencwmC1mPEA7GN88vg3MK5ZHxgLg8kz18SpPvAehdJJc7dmr2fEQuMT9ZzdN57Ne/ UQVy8wEG0ztE+wXxFnghDk/PyXy9hIR2WA3JNYmf0/Rx3TR7ekcXCQVeuear66SWlAxk u53iVsbutsp1fsWmtPBuSbYKqZMSXF/JJUxWdOL35IZA+/AWa/mLGdnhM5o/lQME46ZQ DNbjxlEvDD0odzhnhQgT1ZxBLNM6e9Bee5cV6e0u1bHeMi08bwPCeHVJFtz7CFhKEJ4c T7jw== X-Gm-Message-State: AOAM530h4JqQbjdbRe4QCzGrVyu5L4hzIW2H/U7MtnuYEKyQ2BUgSRDE fmPE3Jb3wYfSABJY01R1VPZoM+LESbv5V0aGAcF0VQ== X-Google-Smtp-Source: ABdhPJzP6/z2Y4B/RMcgHNJSiFwMyyGjU10KSaMnAtQcTRxJV6ksZvT5b4tCLujJ7DZnZs3PkVCBa78PDbRwQv3p+Tg= X-Received: by 2002:aca:1103:: with SMTP id 3mr2428658oir.104.1597129421052; Tue, 11 Aug 2020 00:03:41 -0700 (PDT) From: Muneendra Kumar M References: <1596595862-11075-1-git-send-email-muneendra.kumar@broadcom.com> <1596595862-11075-6-git-send-email-muneendra.kumar@broadcom.com> <2bab689170901076a118204cf05063d5@mail.gmail.com> In-Reply-To: MIME-Version: 1.0 X-Mailer: Microsoft Outlook 15.0 thread-index: AQJ7Mkz9vjBwWq9e6w+xaVY+lMObkwJ+Z0PfAmkI7CECA8cWxQIL+hSbp6E6rSA= Date: Tue, 11 Aug 2020 12:33:38 +0530 Message-ID: <579d6af65acdc2f3cf673d73d00d4694@mail.gmail.com> Subject: RE: [PATCH 5/5] scsi_transport_fc: Added a new sysfs attribute noretries_abort To: Hannes Reinecke , linux-scsi@vger.kernel.org Cc: jsmart2021@gmail.com, emilne@redhat.com, mkumar@redhat.com Content-Type: text/plain; charset="UTF-8" Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Hi Hannes, >> >> Hmm. Wouldn't it make more sense to introduce a new port state 'marginal' >> for this? We might >want/need to introduce additional error recovery >> mechanisms here, so having a new state >might be easier in the long run >> ... > >> Additionally, from my understanding the FPIN events will be generated >> with a certain >frequency. So we could model the new 'marginal' state >> similar to the dev_loss_tmo >mechanism; start a timer whenever the >> 'marginal' state is being set, and clear the state back to >'running' >> if the state hasn't been refreshed within that timeframe. >> That would give us an automatic state reset back to running, and >> quite easy to implement from >userland. > > Thanks for the review. > I have a small doubt. > When the port state moves from marginal to running state does it mean > we expect a traffic from the path ? > >We don't expect traffic; rather we _allow_ traffic. >But moving to from marginal to running means that we didn't receive FPIN >events, and the path should be considered healthy again. >So from that perspective it should be back to normal operations. But this could apply only to FPIN-Congestion. Only in this case FPIN-CN FPIN events will be generated with a certain frequency. But for FPIN-Li this is not the case. FPIN-LI is used to inform about marginal paths, which needs manual intervention to recover. And for FPIN-LI the path should be re-enabled on any link bounce (portdisable followed by portenable) which would correlated to a cable/sfp change. For now, however, we are addressing FPIN-LI primarily. Regards, Muneendra.