From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:45022 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932334AbcILRHD (ORCPT ); Mon, 12 Sep 2016 13:07:03 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Manoj N. Kumar" , "Matthew R. Ochs" , Andrew Donnellan , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 4.4 043/192] [PATCH 044/135] cxlflash: Fix to resolve cmd leak after host reset Date: Mon, 12 Sep 2016 18:59:12 +0200 Message-Id: <20160912152200.735254576@linuxfoundation.org> In-Reply-To: <20160912152158.855601725@linuxfoundation.org> References: <20160912152158.855601725@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit ee91e332a6e6e9b939f60f6e1bd72fb2def5290d ] After a few iterations of resetting the card, either during EEH recovery, or a host_reset the following is seen in the logs. cxlflash 0008:00: cxlflash_queuecommand: could not get a free command At every reset of the card, the commands that are outstanding are being leaked. No effort is being made to reap these commands. A few more resets later, the above error message floods the logs and the card is rendered totally unusable as no free commands are available. Iterated through the 'cmd' queue and printed out the 'free' counter and found that on each reset certain commands were in-use and stayed in-use through subsequent resets. To resolve this issue, when the card is reset, reap all the commands that are active/outstanding. Signed-off-by: Manoj N. Kumar Acked-by: Matthew R. Ochs Reviewed-by: Andrew Donnellan Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/cxlflash/main.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) --- a/drivers/scsi/cxlflash/main.c +++ b/drivers/scsi/cxlflash/main.c @@ -632,15 +632,30 @@ static void free_mem(struct cxlflash_cfg * @cfg: Internal structure associated with the host. * * Safe to call with AFU in a partially allocated/initialized state. + * + * Cleans up all state associated with the command queue, and unmaps + * the MMIO space. + * + * - complete() will take care of commands we initiated (they'll be checked + * in as part of the cleanup that occurs after the completion) + * + * - cmd_checkin() will take care of entries that we did not initiate and that + * have not (and will not) complete because they are sitting on a [now stale] + * hardware queue */ static void stop_afu(struct cxlflash_cfg *cfg) { int i; struct afu *afu = cfg->afu; + struct afu_cmd *cmd; if (likely(afu)) { - for (i = 0; i < CXLFLASH_NUM_CMDS; i++) - complete(&afu->cmd[i].cevent); + for (i = 0; i < CXLFLASH_NUM_CMDS; i++) { + cmd = &afu->cmd[i]; + complete(&cmd->cevent); + if (!atomic_read(&cmd->free)) + cmd_checkin(cmd); + } if (likely(afu->afu_map)) { cxl_psa_unmap((void __iomem *)afu->afu_map);