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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C7490C3814E for ; Tue, 23 Aug 2022 10:47:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356121AbiHWKqd (ORCPT ); Tue, 23 Aug 2022 06:46:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52752 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355200AbiHWKkC (ORCPT ); Tue, 23 Aug 2022 06:40:02 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE689A723B; Tue, 23 Aug 2022 02:08:03 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 7327FB81C4E; Tue, 23 Aug 2022 09:08:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C0B7BC433C1; Tue, 23 Aug 2022 09:08:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661245681; bh=8oectIyZt6VRJD/c0vemqJWQCt3u+kU50lQPATG608M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gttL7T/jly3XWt+Qf0z0zDMzprTDmEPwc1GLMYrMcb07KyeK2Dikhhz6LHKPet2P8 Xiua3sjsg9wB5s905arL6N8FP/fnkWH9V5SkfRFSXu5VlWspMNMCOIBVY2dEiZhgPJ Hjk3/9ntOT7egLL/llkI6M+H7Rdv5cBwPbuUh5UY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Farman , Matthew Rosato , Alex Williamson , Sasha Levin Subject: [PATCH 4.19 156/287] vfio/ccw: Do not change FSM state in subchannel event Date: Tue, 23 Aug 2022 10:25:25 +0200 Message-Id: <20220823080105.905442984@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080100.268827165@linuxfoundation.org> References: <20220823080100.268827165@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Farman [ Upstream commit cffcc109fd682075dee79bade3d60a07152a8fd1 ] The routine vfio_ccw_sch_event() is tasked with handling subchannel events, specifically machine checks, on behalf of vfio-ccw. It correctly calls cio_update_schib(), and if that fails (meaning the subchannel is gone) it makes an FSM event call to mark the subchannel Not Operational. If that worked, however, then it decides that if the FSM state was already Not Operational (implying the subchannel just came back), then it should simply change the FSM to partially- or fully-open. Remove this trickery, since a subchannel returning will require more probing than simply "oh all is well again" to ensure it works correctly. Fixes: bbe37e4cb8970 ("vfio: ccw: introduce a finite state machine") Signed-off-by: Eric Farman Reviewed-by: Matthew Rosato Link: https://lore.kernel.org/r/20220707135737.720765-4-farman@linux.ibm.com Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin --- drivers/s390/cio/vfio_ccw_drv.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index 7a06cdff6572..862b0eb0fe6d 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -205,19 +205,11 @@ static int vfio_ccw_sch_event(struct subchannel *sch, int process) if (work_pending(&sch->todo_work)) goto out_unlock; - if (cio_update_schib(sch)) { - vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER); - rc = 0; - goto out_unlock; - } - - private = dev_get_drvdata(&sch->dev); - if (private->state == VFIO_CCW_STATE_NOT_OPER) { - private->state = private->mdev ? VFIO_CCW_STATE_IDLE : - VFIO_CCW_STATE_STANDBY; - } rc = 0; + if (cio_update_schib(sch)) + vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER); + out_unlock: spin_unlock_irqrestore(sch->lock, flags); -- 2.35.1