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Date:   Mon, 27 Apr 2020 10:21:02 +0000
From:   Wei Liu <wei.liu@kernel.org>
To:     Wei Hu <weh@microsoft.com>
Cc:     kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com,
        wei.liu@kernel.org, lorenzo.pieralisi@arm.com, robh@kernel.org,
        bhelgaas@google.com, linux-hyperv@vger.kernel.org,
        linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
        decui@microsoft.com, mikelley@microsoft.com
Subject: Re: [PATCH] PCI: pci-hyperv: Retry PCI bus D0 entry when the first
 attempt failed with invalid device state 0xC0000184.
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References: <20200426132430.1756-1-weh@microsoft.com>
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On Sun, Apr 26, 2020 at 09:24:30PM +0800, Wei Hu wrote:
> In the case of kdump, the PCI device was not cleanly shut down
> before the kdump kernel starts. This causes the initial
> attempt of entering D0 state in the kdump kernel to fail with
> invalid device state 0xC0000184 returned from Hyper-V host.
> When this happens, explicitly call PCI bus exit and retry to
> enter the D0 state.
> 
> Also fix the PCI probe failure path to release the PCI device
> resource properly.
> 
> Signed-off-by: Wei Hu <weh@microsoft.com>
> ---
>  drivers/pci/controller/pci-hyperv.c | 34 ++++++++++++++++++++++++++++-
>  1 file changed, 33 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
> index e15022ff63e3..eb4781fa058d 100644
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -2736,6 +2736,10 @@ static void hv_free_config_window(struct hv_pcibus_device *hbus)
>  	vmbus_free_mmio(hbus->mem_config->start, PCI_CONFIG_MMIO_LENGTH);
>  }
>  
> +#define STATUS_INVALID_DEVICE_STATE		0xC0000184
> +

Can you please move this along side STATUS_REVISION_MISMATCH?

Wei.