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Date: Wed, 8 Feb 2017 09:49:51 +0800
From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
To: Ferruh Yigit <ferruh.yigit@intel.com>
Cc: Qi Zhang <qi.z.zhang@intel.com>, jingjing.wu@intel.com,
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 Thomas Monjalon <thomas.monjalon@6wind.com>
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Subject: Re: [dpdk-dev] [PATCH] net/i40e: fix wrong device flag setup
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On Tue, Feb 07, 2017 at 10:32:32AM +0000, Ferruh Yigit wrote:
> On 2/7/2017 10:24 AM, Ferruh Yigit wrote:
> > On 2/3/2017 11:36 PM, Qi Zhang wrote:
> >> dev_flags is wrong overwritten by RTE_ETH_DEV_DETACHABLE after
> >> rte_eth_copy_pci_info.
> >>
...
> Hi Yuanhan,
> 
> I saw while checking for this, there can be an issue in virtio for this
> path, can you please check:
> 
> eth_virtio_dev_init()
>   set-some-eth_dev-dev_flags
>   virtio_init_device()
>     rte_eth_copy_pci_info()
>       eth_dev->data->dev_flags = 0;   <---- Reset previous flags

Hi Ferruh,

Nice catch! And yes, it's buggy. It may be trivially fixed by setting
the orders correctly. But my question is why "rte_eth_copy_pci_info"
does a reset on "dev_flags"? It's an *un-documented* side-effect of
this function, which could be very error-prone, like this one.

	--yliu