From patchwork Mon Sep 14 07:56:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tiezhu Yang X-Patchwork-Id: 11773189 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 99DC0159A for ; Mon, 14 Sep 2020 07:57:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 83D8621741 for ; Mon, 14 Sep 2020 07:57:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726093AbgINH5T (ORCPT ); Mon, 14 Sep 2020 03:57:19 -0400 Received: from mail.loongson.cn ([114.242.206.163]:40826 "EHLO loongson.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726068AbgINH5S (ORCPT ); Mon, 14 Sep 2020 03:57:18 -0400 Received: from linux.localdomain (unknown [113.200.148.30]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9Dxz99IIl9fbiUVAA--.4831S2; Mon, 14 Sep 2020 15:56:56 +0800 (CST) From: Tiezhu Yang To: Bjorn Helgaas Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , Konstantin Khlebnikov , Khalid Aziz , Vivek Goyal , Lukas Wunner , Oliver O'Halloran , Huacai Chen , Jiaxun Yang , Xuefeng Li Subject: [RFC PATCH v3] PCI/portdrv: Only disable Bus Master on kexec reboot and connected PCI devices Date: Mon, 14 Sep 2020 15:56:55 +0800 Message-Id: <1600070215-3901-1-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 X-CM-TRANSID: AQAAf9Dxz99IIl9fbiUVAA--.4831S2 X-Coremail-Antispam: 1UD129KBjvJXoWxWF1fKFyxGFyUCw1kZrykAFb_yoWrXw4rpa yUJF9FyrW0qry2gr43tFyUXa45JanFya4IyryxG343ur4xCFy0yrWxtFyavw1DJrZYvFy7 JayDt3y8GFWUJF7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvE14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26r4j6ryUM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26F4j 6r4UJwA2z4x0Y4vEx4A2jsIE14v26F4UJVW0owA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gc CE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E 2Ix0cI8IcVAFwI0_JrI_JrylYx0Ex4A2jsIE14v26r4j6F4UMcvjeVCFs4IE7xkEbVWUJV W8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lFIxGxcIEc7CjxVA2 Y2ka0xkIwI1lc2xSY4AK67AK6r4xMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r 1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CE b7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0x vE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_WFyUJVCq3wCI 42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWI evJa73UjIFyTuYvjfUYgAwDUUUU X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org After commit 745be2e700cd ("PCIe: portdrv: call pci_disable_device during remove") and commit cc27b735ad3a ("PCI/portdrv: Turn off PCIe services during shutdown"), it also calls pci_disable_device() during shutdown, this leads to shutdown or reboot failure occasionally due to clear PCI_COMMAND_MASTER on the device in do_pci_disable_device(). drivers/pci/pci.c static void do_pci_disable_device(struct pci_dev *dev) { u16 pci_command; pci_read_config_word(dev, PCI_COMMAND, &pci_command); if (pci_command & PCI_COMMAND_MASTER) { pci_command &= ~PCI_COMMAND_MASTER; pci_write_config_word(dev, PCI_COMMAND, pci_command); } pcibios_disable_device(dev); } When remove "pci_command &= ~PCI_COMMAND_MASTER;", it can work well when shutdown or reboot. As Oliver O'Halloran said, no need to call pci_disable_device() when actually shutting down, but we should call pci_disable_device() before handing over to the new kernel on kexec reboot, so we can do some condition checks which are already executed afterwards by the function pci_device_shutdown(), this is done by commit 4fc9bbf98fd6 ("PCI: Disable Bus Master only on kexec reboot") and commit 6e0eda3c3898 ("PCI: Don't try to disable Bus Master on disconnected PCI devices"). drivers/pci/pci-driver.c static void pci_device_shutdown(struct device *dev) { ... if (drv && drv->shutdown) drv->shutdown(pci_dev); /* * If this is a kexec reboot, turn off Bus Master bit on the * device to tell it to not continue to do DMA. Don't touch * devices in D3cold or unknown states. * If it is not a kexec reboot, firmware will hit the PCI * devices with big hammer and stop their DMA any way. */ if (kexec_in_progress && (pci_dev->current_state <= PCI_D3hot)) pci_clear_master(pci_dev); } [ 36.159446] Call Trace: [ 36.241688] [] show_stack+0x9c/0x130 [ 36.326619] [] dump_stack+0xb0/0xf0 [ 36.410403] [] pcie_portdrv_shutdown+0x18/0x78 [ 36.495302] [] pci_device_shutdown+0x44/0x90 [ 36.580027] [] device_shutdown+0x130/0x290 [ 36.664486] [] kernel_power_off+0x38/0x80 [ 36.748272] [] __do_sys_reboot+0x1a4/0x258 [ 36.831985] [] syscall_common+0x34/0x58 Signed-off-by: Tiezhu Yang Signed-off-by: Tiezhu Yang --- drivers/pci/pcie/portdrv_core.c | 1 - drivers/pci/pcie/portdrv_pci.c | 14 +++++++++++++- 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c index 50a9522..1991aca 100644 --- a/drivers/pci/pcie/portdrv_core.c +++ b/drivers/pci/pcie/portdrv_core.c @@ -491,7 +491,6 @@ void pcie_port_device_remove(struct pci_dev *dev) { device_for_each_child(&dev->dev, NULL, remove_iter); pci_free_irq_vectors(dev); - pci_disable_device(dev); } /** diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c index 3a3ce40..cab37a8 100644 --- a/drivers/pci/pcie/portdrv_pci.c +++ b/drivers/pci/pcie/portdrv_pci.c @@ -143,6 +143,18 @@ static void pcie_portdrv_remove(struct pci_dev *dev) } pcie_port_device_remove(dev); + pci_disable_device(dev); +} + +static void pcie_portdrv_shutdown(struct pci_dev *dev) +{ + if (pci_bridge_d3_possible(dev)) { + pm_runtime_forbid(&dev->dev); + pm_runtime_get_noresume(&dev->dev); + pm_runtime_dont_use_autosuspend(&dev->dev); + } + + pcie_port_device_remove(dev); } static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev, @@ -211,7 +223,7 @@ static struct pci_driver pcie_portdriver = { .probe = pcie_portdrv_probe, .remove = pcie_portdrv_remove, - .shutdown = pcie_portdrv_remove, + .shutdown = pcie_portdrv_shutdown, .err_handler = &pcie_portdrv_err_handler,