From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:53362 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031344AbeEXKD5 (ORCPT ); Thu, 24 May 2018 06:03:57 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dick Kennedy , James Smart , Hannes Reinecke , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 4.16 114/161] scsi: lpfc: Fix soft lockup in lpfc worker thread during LIP testing Date: Thu, 24 May 2018 11:38:59 +0200 Message-Id: <20180524093031.975849318@linuxfoundation.org> In-Reply-To: <20180524093018.331893860@linuxfoundation.org> References: <20180524093018.331893860@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: James Smart [ Upstream commit 161df4f09987ae2e9f0f97f0b38eee298b4a39ff ] During link bounce testing in a point-to-point topology, the host may enter a soft lockup on the lpfc_worker thread: Call Trace: lpfc_work_done+0x1f3/0x1390 [lpfc] lpfc_do_work+0x16f/0x180 [lpfc] kthread+0xc7/0xe0 ret_from_fork+0x3f/0x70 The driver was simultaneously setting a combination of flags that caused lpfc_do_work()to effectively spin between slow path work and new event data, causing the lockup. Ensure in the typical wq completions, that new event data flags are set if the slow path flag is running. The slow path will eventually reschedule the wq handling. Signed-off-by: Dick Kennedy Signed-off-by: James Smart Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/lpfc/lpfc_hbadisc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/scsi/lpfc/lpfc_hbadisc.c +++ b/drivers/scsi/lpfc/lpfc_hbadisc.c @@ -696,8 +696,9 @@ lpfc_work_done(struct lpfc_hba *phba) phba->hba_flag & HBA_SP_QUEUE_EVT)) { if (pring->flag & LPFC_STOP_IOCB_EVENT) { pring->flag |= LPFC_DEFERRED_RING_EVENT; - /* Set the lpfc data pending flag */ - set_bit(LPFC_DATA_READY, &phba->data_flags); + /* Preserve legacy behavior. */ + if (!(phba->hba_flag & HBA_SP_QUEUE_EVT)) + set_bit(LPFC_DATA_READY, &phba->data_flags); } else { if (phba->link_state >= LPFC_LINK_UP || phba->link_flag & LS_MDS_LOOPBACK) {