[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CAFv23Q=4O5czQaNw2mEnwkb9LQfODfQDeW+qQD14rfdeVEwjwA@mail.gmail.com>
Date: Mon, 7 Oct 2024 12:34:09 +0800
From: AceLan Kao <acelan.kao@...onical.com>
To: Lukas Wunner <lukas@...ner.de>
Cc: Bjorn Helgaas <bhelgaas@...gle.com>, Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] PCI: pciehp: Fix system hang on resume after hot-unplug
during suspend
Lukas Wunner <lukas@...ner.de> 於 2024年10月1日 週二 下午7:03寫道:
>
> On Tue, Oct 01, 2024 at 01:02:46PM +0200, Lukas Wunner wrote:
> > On Mon, Sep 30, 2024 at 09:31:53AM +0800, AceLan Kao wrote:
> > > Lukas Wunner <lukas@...ner.de> 2024 9 28 8:51:
> > > > - if (pci_get_dsn(pdev) != ctrl->dsn)
> > > > + dsn = pci_get_dsn(pdev);
> > > > + if (!PCI_POSSIBLE_ERROR(dsn) &&
> > > > + dsn != ctrl->dsn)
> > > > return true;
> > >
> > > In my case, the pciehp_device_replaced() returns true from this final check.
> > > And these are the values I got
> > > dsn = 0x00000000, ctrl->dsn = 0x7800AA00
> > > dsn = 0x00000000, ctrl->dsn = 0x21B7D000
> >
> > Ah because pci_get_dsn() returns 0 if the device is gone.
> > Below is a modified patch which returns false in that case.
>
> Sorry, forgot to include the patch:
>
> -- >8 --
>
> diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
> index ff458e6..957c320 100644
> --- a/drivers/pci/hotplug/pciehp_core.c
> +++ b/drivers/pci/hotplug/pciehp_core.c
> @@ -287,24 +287,32 @@ static int pciehp_suspend(struct pcie_device *dev)
> static bool pciehp_device_replaced(struct controller *ctrl)
> {
> struct pci_dev *pdev __free(pci_dev_put);
> + u64 dsn;
> u32 reg;
>
> pdev = pci_get_slot(ctrl->pcie->port->subordinate, PCI_DEVFN(0, 0));
> if (!pdev)
> + return false;
> +
> + if (pci_read_config_dword(pdev, PCI_VENDOR_ID, ®) == 0 &&
> + !PCI_POSSIBLE_ERROR(reg) &&
> + reg != (pdev->vendor | (pdev->device << 16)))
> return true;
>
> - if (pci_read_config_dword(pdev, PCI_VENDOR_ID, ®) ||
> - reg != (pdev->vendor | (pdev->device << 16)) ||
> - pci_read_config_dword(pdev, PCI_CLASS_REVISION, ®) ||
> + if (pci_read_config_dword(pdev, PCI_CLASS_REVISION, ®) == 0 &&
> + !PCI_POSSIBLE_ERROR(reg) &&
> reg != (pdev->revision | (pdev->class << 8)))
> return true;
>
> if (pdev->hdr_type == PCI_HEADER_TYPE_NORMAL &&
> - (pci_read_config_dword(pdev, PCI_SUBSYSTEM_VENDOR_ID, ®) ||
> - reg != (pdev->subsystem_vendor | (pdev->subsystem_device << 16))))
> + pci_read_config_dword(pdev, PCI_SUBSYSTEM_VENDOR_ID, ®) == 0 &&
> + !PCI_POSSIBLE_ERROR(reg) &&
> + reg != (pdev->subsystem_vendor | (pdev->subsystem_device << 16)))
> return true;
>
> - if (pci_get_dsn(pdev) != ctrl->dsn)
> + if ((dsn = pci_get_dsn(pdev)) &&
> + !PCI_POSSIBLE_ERROR(dsn) &&
> + dsn != ctrl->dsn)
> return true;
>
> return false;
Hi Lukas,
Sorry for the late reply, just encountered a strong typhoon in my area
last week and can't check this in our lab.
The patched pciehp_device_replaced() returns false at the end of the
function in my case.
Unplug the dock which is connected with a tbt storage won't be
considered as a replacement.
But when I tried to replace the dock with the tbt storage during
suspend, it still returned false at the end of the function like
unplugged.
BTW, it's a new model, so I think the ICM is used. And the reg is
0xffffffff when unplugged.
Powered by blists - more mailing lists