lkml.org 
[lkml]   [2020]   [Sep]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [RFC PATCH v2] PCI/portdrv: Only disable Bus Master on kexec reboot and connected PCI devices
From
Date
On 09/14/2020 02:13 PM, Tiezhu Yang wrote:
> 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.

Sorry, I misunderstood your meaning, you are right.

>
>
> 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

\
 
 \ /
  Last update: 2020-09-14 08:33    [W:0.037 / U:0.784 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site