From: Tiezhu Yang <yangtiezhu@loongson.cn>
To: Lukas Wunner <lukas@wunner.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
Konstantin Khlebnikov <khlebnikov@openvz.org>,
Khalid Aziz <khalid.aziz@oracle.com>,
Vivek Goyal <vgoyal@redhat.com>,
oohall@gmail.com, rafael.j.wysocki@intel.com,
Xuefeng Li <lixuefeng@loongson.cn>,
Huacai Chen <chenhc@lemote.com>,
Jiaxun Yang <jiaxun.yang@flygoat.com>,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH v2] PCI/portdrv: Only disable Bus Master on kexec reboot and connected PCI devices
Date: Mon, 14 Sep 2020 14:13:31 +0800 [thread overview]
Message-ID: <43683243-f8e2-c555-447a-f108740c70e8@loongson.cn> (raw)
In-Reply-To: <20200914040625.GA20033@wunner.de>
On 09/14/2020 12:06 PM, Lukas Wunner wrote:
> On Mon, Sep 14, 2020 at 04:29:10AM +0800, Tiezhu Yang wrote:
>> --- a/drivers/pci/pcie/portdrv_pci.c
>> +++ b/drivers/pci/pcie/portdrv_pci.c
>> @@ -143,6 +144,28 @@ 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);
>> +
>> + /*
>> + * 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 && (dev->current_state <= PCI_D3hot))
>> + pci_disable_device(dev);
> The last portion of this function is already executed afterwards by
> pci_device_shutdown(). You don't need to duplicate it here:
>
> device_shutdown()
> dev->bus->shutdown() == pci_device_shutdown()
> drv->shutdown() == pcie_portdrv_shutdown()
> pci_disable_device()
> pci_disable_device()
pcie_port_device_remove() deletes pci_disable_device(dev) at the beginning of this patch.
diff
<https://lore.kernel.org/linux-pci/CAAhV-H5-X9OcBe3iRxF8PnKW-0j_10FVqm8cbiqW2-Lv4mTTdQ@mail.gmail.com/T/#iZ2e.:..:1600028950-10644-1-git-send-email-yangtiezhu::40loongson.cn:0drivers:pci:pcie:portdrv_core.c>
--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); }
>
> Thanks,
>
> Lukas
next prev parent reply other threads:[~2020-09-14 6:13 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-13 20:29 [RFC PATCH v2] PCI/portdrv: Only disable Bus Master on kexec reboot and connected PCI devices Tiezhu Yang
2020-09-14 4:06 ` Lukas Wunner
2020-09-14 6:13 ` Tiezhu Yang [this message]
2020-09-14 6:30 ` Tiezhu Yang
[not found] ` <tencent_44F0201A70619BA613F16BA4@qq.com>
2020-09-14 4:31 ` Huacai Chen
2020-09-14 6:17 ` Tiezhu Yang
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