From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S969233AbeEXLnU (ORCPT ); Thu, 24 May 2018 07:43:20 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:39348 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S969169AbeEXLnL (ORCPT ); Thu, 24 May 2018 07:43:11 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org EE70E601D4 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=okaya@codeaurora.org Subject: Re: [PATCH V2] PCI/portdrv: do not disable device on reboot/shutdown To: Bjorn Helgaas Cc: linux-pci@vger.kernel.org, timur@codeaurora.org, ryan@finnie.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, stable@vger.kernel.org, Bjorn Helgaas , "Rafael J. Wysocki" , Greg Kroah-Hartman , Thomas Gleixner , Kate Stewart , Frederick Lawler , Dongdong Liu , Mika Westerberg , open list , Don Brace , esc.storagedev@microsemi.com, linux-scsi@vger.kernel.org References: <1527043490-17268-1-git-send-email-okaya@codeaurora.org> <20180523213249.GD150632@bhelgaas-glaptop.roam.corp.google.com> <61f70fd6-52fd-da07-ce73-303f95132131@codeaurora.org> From: Sinan Kaya Message-ID: <82656e20-e821-1944-3399-1667ceb27719@codeaurora.org> Date: Thu, 24 May 2018 07:43:05 -0400 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <61f70fd6-52fd-da07-ce73-303f95132131@codeaurora.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/23/2018 6:57 PM, Sinan Kaya wrote: >> The crash seems to indicate that the hpsa device attempted a DMA after >> we cleared the Root Port's PCI_COMMAND_MASTER, which means >> hpsa_shutdown() didn't stop DMA from the device (it looks like *most* >> shutdown methods don't disable device DMA, so it's in good company). > All drivers are expected to shutdown DMA and interrupts in their shutdown() > routines. They can skip removing threads, data structures etc. but DMA and > interrupt disabling are required. This is the difference between shutdown() > and remove() callbacks. I found this note yesterday to see why we are not disabling the devices in the PCI core itself. pci_device_remove() /* * We would love to complain here if pci_dev->is_enabled is set, that * the driver should have called pci_disable_device(), but the * unfortunate fact is there are too many odd BIOS and bridge setups * that don't like drivers doing that all of the time. * Oh well, we can dream of sane hardware when we sleep, no matter how * horrible the crap we have to deal with is when we are awake... */ Ryan, can you discard the previous patch and test this one instead? remove() path in hpsa driver seems to call pci_disable_device() via hpsa_remove_one() hpsa_free_pci_init() but nothing on the shutdown path. diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c index 4ed3d26..3823f04 100644 --- a/drivers/scsi/hpsa.c +++ b/drivers/scsi/hpsa.c @@ -8651,6 +8651,7 @@ static void hpsa_shutdown(struct pci_dev *pdev) h->access.set_intr_mask(h, HPSA_INTR_OFF); hpsa_free_irqs(h); /* init_one 4 */ hpsa_disable_interrupt_mode(h); /* pci_init 2 */ + pci_disable_device(h->pdev); } -- Sinan Kaya Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.