From patchwork Thu May 9 15:36:31 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frank Heimes X-Patchwork-Id: 1097552 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 450HWZ3g71z9sBp; Fri, 10 May 2019 01:36:42 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1hOl65-00040Q-Sz; Thu, 09 May 2019 15:36:37 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.86_2) (envelope-from ) id 1hOl64-000407-8c for kernel-team@lists.ubuntu.com; Thu, 09 May 2019 15:36:36 +0000 Received: from 2.general.fheimes.uk.vpn ([10.172.194.67] helo=localhost.localdomain) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1hOl63-0006AM-TD for kernel-team@lists.ubuntu.com; Thu, 09 May 2019 15:36:36 +0000 From: frank.heimes@canonical.com To: kernel-team@lists.ubuntu.com Subject: [SRU][Bionic][Patch 1/1] s390/qdio: clear intparm during shutdown Date: Thu, 9 May 2019 17:36:31 +0200 Message-Id: <1557416191-21935-2-git-send-email-frank.heimes@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1557416191-21935-1-git-send-email-frank.heimes@canonical.com> References: <1557416191-21935-1-git-send-email-frank.heimes@canonical.com> X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Julian Wiedmann BugLink: https://bugs.launchpad.net/bugs/1828394 During shutdown, qdio returns its ccw device back to control by the upper-layer driver. But there is a remote chance that by the time where the IRQ handler gets switched back, the interrupt for the preceding ccw_device_{clear,halt} hasn't been presented yet. Upper-layer drivers would then need to handle this IRQ - and since the IO is issued with an intparm, it could very well be confused with whatever intparm mechanism the driver uses itself (eg intparm == request address). So when switching over the IRQ handler, also clear the intparm and have upper-layer drivers deal with any such delayed interrupt as if it was unsolicited. Suggested-by: Sebastian Ott Signed-off-by: Julian Wiedmann Signed-off-by: Martin Schwidefsky (cherry picked from commit 89286320a236d245834075fa13adb0bdd827ecaa) Signed-off-by: Frank Heimes Acked-by: Connor Kuehl Acked-by: Kleber Sacilotto de Souza --- drivers/s390/cio/qdio_main.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c index d76df58..8842be6 100644 --- a/drivers/s390/cio/qdio_main.c +++ b/drivers/s390/cio/qdio_main.c @@ -1218,8 +1218,10 @@ int qdio_shutdown(struct ccw_device *cdev, int how) qdio_shutdown_thinint(irq_ptr); /* restore interrupt handler */ - if ((void *)cdev->handler == (void *)qdio_int_handler) + if ((void *)cdev->handler == (void *)qdio_int_handler) { cdev->handler = irq_ptr->orig_handler; + cdev->private->intparm = 0; + } spin_unlock_irq(get_ccwdev_lock(cdev)); qdio_set_state(irq_ptr, QDIO_IRQ_STATE_INACTIVE);