[dpdk-dev,v2] doc: add known uio_pci_generic issue for i40e

  From: "Guo, Jia" <jia.guo@intel.com>

When bind with uio_pci_generic in X710/XL710/XXV710, the result
is failed. uio_pci_generic is not supported by X710/XL710/XXV710.

Signed-off-by: Guo, Jia <jia.guo@intel.com>
---
v2: add X710/XXV710 limitation case
---
 doc/guides/rel_notes/known_issues.rst | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
  

On 2/12/2016 4:39 PM, Jeff Guo wrote:
> From: "Guo, Jia" <jia.guo@intel.com>
> 
> When bind with uio_pci_generic in X710/XL710/XXV710, the result
> is failed. uio_pci_generic is not supported by X710/XL710/XXV710.

Hi Jeff,

There is a Linux commit causing the issue, right. Commit done because of
the reasons mentioned in "Description". Do you think does it make sense
to note that Linux commit, and Linux kernel version that has been
introduced?

> 
> Signed-off-by: Guo, Jia <jia.guo@intel.com>

You are known as "Jeff Guo <jia.guo@intel.com>" to DPDK repo, based on
previous commits.
If this is correct, is there any problem to continue like this?

> ---
> v2: add X710/XXV710 limitation case

Also v1 Acked-by JingJing already, you can keep her ack in next version
of the patch.

> ---
>  doc/guides/rel_notes/known_issues.rst | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
> 
> diff --git a/doc/guides/rel_notes/known_issues.rst b/doc/guides/rel_notes/known_issues.rst
> index 3cd4237..1751451 100644
> --- a/doc/guides/rel_notes/known_issues.rst
> +++ b/doc/guides/rel_notes/known_issues.rst
> @@ -640,3 +640,27 @@ I40e VF may not receive packets in the promiscuous mode
>  
>  **Driver/Module**:
>     Poll Mode Driver (PMD).
> +
> +
> +uio_pci_generic bind failed in X710/XL710/XXV710
> +-------------------------------------------------------
> +
> +**Description**:
> +   uio_pci_generic is not supported by XL710, since the errata of XL710 that the feature
> +   about the Interrupt Status bit is not implemented.The errata is the item #71 from the
> +   `xl710 controller spec  <http://www.intel.com/content/www/us/en/embedded/products/networking/xl710-10-40-controller-spec-update.html>`_.
> +   The hw limitation is the same as other X710/XXV710 NICs.
> +
> +**Implication**:
> +   When bind uio_pci_generic, the uio_pci_generic probe device and check the Interrupt
> +   Status bit related feature of NICs , since it is not supported by X710/XL710/XXV710,
> +   so it return failed.
> +
> +**Resolution/Workaround**:
> +   Do not bind to use uio_pci_generic in X710/XL710/XXV710 NICs.
> +
> +**Affected Environment/Platform**:
> +   All.
> +
> +**Driver/Module**:
> +   Poll Mode Driver (PMD).
>
  

> -----Original Message-----
> From: Yigit, Ferruh
> Sent: Tuesday, January 17, 2017 4:31 AM
> To: Guo, Jia <jia.guo@intel.com>; Zhang, Helin <helin.zhang@intel.com>; Wu,
> Jingjing <jingjing.wu@intel.com>
> Cc: dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v2] doc: add known uio_pci_generic issue
> for i40e
> 
> On 2/12/2016 4:39 PM, Jeff Guo wrote:
> > From: "Guo, Jia" <jia.guo@intel.com>
> >
> > When bind with uio_pci_generic in X710/XL710/XXV710, the result is
> > failed. uio_pci_generic is not supported by X710/XL710/XXV710.
> 
> Hi Jeff,
> 
> There is a Linux commit causing the issue, right. Commit done because of the
> reasons mentioned in "Description". Do you think does it make sense to note
> that Linux commit, and Linux kernel version that has been introduced?
> 
Hi, Ferruh
At beginning, we found this issue in latest kernel version, such as kernel 4.7.9 on fedora24.
But later, we observed that this issue also exist on REL7.3.
So, it may be a little difficult to us to figure out exactly which kernel version
doesn't support. And the root cause is the HW's errata which makes uio_pci_generic
cannot be used on XL710 series NICs.

Thanks
Jingjing
  

On 1/17/2017 5:00 PM, Wu, Jingjing wrote:
> 
> 
>> -----Original Message-----
>> From: Yigit, Ferruh
>> Sent: Tuesday, January 17, 2017 4:31 AM
>> To: Guo, Jia <jia.guo@intel.com>; Zhang, Helin <helin.zhang@intel.com>; Wu,
>> Jingjing <jingjing.wu@intel.com>
>> Cc: dev@dpdk.org
>> Subject: Re: [dpdk-dev] [PATCH v2] doc: add known uio_pci_generic issue
>> for i40e
>>
>> On 2/12/2016 4:39 PM, Jeff Guo wrote:
>>> From: "Guo, Jia" <jia.guo@intel.com>
>>>
>>> When bind with uio_pci_generic in X710/XL710/XXV710, the result is
>>> failed. uio_pci_generic is not supported by X710/XL710/XXV710.
>>
>> Hi Jeff,
>>
>> There is a Linux commit causing the issue, right. Commit done because of the
>> reasons mentioned in "Description". Do you think does it make sense to note
>> that Linux commit, and Linux kernel version that has been introduced?
>>
> Hi, Ferruh
> At beginning, we found this issue in latest kernel version, such as kernel 4.7.9 on fedora24.
> But later, we observed that this issue also exist on REL7.3.

It won't work custom kernels, but upstream kernel version. If you think
that will be confusion, that is OK.

What do you think just adding Linux kernel commit information, can it be
useful?

> So, it may be a little difficult to us to figure out exactly which kernel version
> doesn't support. And the root cause is the HW's errata which makes uio_pci_generic
> cannot be used on XL710 series NICs.
> 
> Thanks
> Jingjing
>
  

On 1/18/2017 1:36 AM, Ferruh Yigit wrote:
> On 1/17/2017 5:00 PM, Wu, Jingjing wrote:
>>
>>> -----Original Message-----
>>> From: Yigit, Ferruh
>>> Sent: Tuesday, January 17, 2017 4:31 AM
>>> To: Guo, Jia <jia.guo@intel.com>; Zhang, Helin <helin.zhang@intel.com>; Wu,
>>> Jingjing <jingjing.wu@intel.com>
>>> Cc: dev@dpdk.org
>>> Subject: Re: [dpdk-dev] [PATCH v2] doc: add known uio_pci_generic issue
>>> for i40e
>>>
>>> On 2/12/2016 4:39 PM, Jeff Guo wrote:
>>>> From: "Guo, Jia" <jia.guo@intel.com>
>>>>
>>>> When bind with uio_pci_generic in X710/XL710/XXV710, the result is
>>>> failed. uio_pci_generic is not supported by X710/XL710/XXV710.
>>> Hi Jeff,
>>>
>>> There is a Linux commit causing the issue, right. Commit done because of the
>>> reasons mentioned in "Description". Do you think does it make sense to note
>>> that Linux commit, and Linux kernel version that has been introduced?
>>>
>> Hi, Ferruh
>> At beginning, we found this issue in latest kernel version, such as kernel 4.7.9 on fedora24.
>> But later, we observed that this issue also exist on REL7.3.
> It won't work custom kernels, but upstream kernel version. If you think
> that will be confusion, that is OK.
>
> What do you think just adding Linux kernel commit information, can it be
> useful?
yes, the root cause of the issue is the HW' errata, but not the linux 
kernel commit,  because even without the linux kernel commit and 
uio_pci_generic can even be bind and use,  but still will cause other 
interrupt status issue. fix this interrupt status issue that is the 
purpose of the linux kernel commit.
so i think add linux kernel commit information in dpdk can be somehow to 
useful for track issue, but if let the kernel issue be manage by kernel 
org must be better.
ferruh and jingjing, Do you all agree with me. beg on your feedback.
>> So, it may be a little difficult to us to figure out exactly which kernel version
>> doesn't support. And the root cause is the HW's errata which makes uio_pci_generic
>> cannot be used on XL710 series NICs.
>>
>> Thanks
>> Jingjing
>>
  

On 1/18/2017 2:48 AM, Guo, Jia wrote:
> 
> 
> On 1/18/2017 1:36 AM, Ferruh Yigit wrote:
>> On 1/17/2017 5:00 PM, Wu, Jingjing wrote:
>>>
>>>> -----Original Message-----
>>>> From: Yigit, Ferruh
>>>> Sent: Tuesday, January 17, 2017 4:31 AM
>>>> To: Guo, Jia <jia.guo@intel.com>; Zhang, Helin <helin.zhang@intel.com>; Wu,
>>>> Jingjing <jingjing.wu@intel.com>
>>>> Cc: dev@dpdk.org
>>>> Subject: Re: [dpdk-dev] [PATCH v2] doc: add known uio_pci_generic issue
>>>> for i40e
>>>>
>>>> On 2/12/2016 4:39 PM, Jeff Guo wrote:
>>>>> From: "Guo, Jia" <jia.guo@intel.com>
>>>>>
>>>>> When bind with uio_pci_generic in X710/XL710/XXV710, the result is
>>>>> failed. uio_pci_generic is not supported by X710/XL710/XXV710.
>>>> Hi Jeff,
>>>>
>>>> There is a Linux commit causing the issue, right. Commit done because of the
>>>> reasons mentioned in "Description". Do you think does it make sense to note
>>>> that Linux commit, and Linux kernel version that has been introduced?
>>>>
>>> Hi, Ferruh
>>> At beginning, we found this issue in latest kernel version, such as kernel 4.7.9 on fedora24.
>>> But later, we observed that this issue also exist on REL7.3.
>> It won't work custom kernels, but upstream kernel version. If you think
>> that will be confusion, that is OK.
>>
>> What do you think just adding Linux kernel commit information, can it be
>> useful?
> yes, the root cause of the issue is the HW' errata, but not the linux 
> kernel commit,  because even without the linux kernel commit and 
> uio_pci_generic can even be bind and use,  but still will cause other 
> interrupt status issue. fix this interrupt status issue that is the 
> purpose of the linux kernel commit.
> so i think add linux kernel commit information in dpdk can be somehow to 
> useful for track issue, 

That was my reasoning for asking this. It may help others to understand
the issue more.

But is seems both you and Jingjing think this cause more confusion than
benefit. So I am OK with your proposal, if nobody else have objection.

> but if let the kernel issue be manage by kernel 
> org must be better.
> ferruh and jingjing, Do you all agree with me. beg on your feedback.
>>> So, it may be a little difficult to us to figure out exactly which kernel version
>>> doesn't support. And the root cause is the HW's errata which makes uio_pci_generic
>>> cannot be used on XL710 series NICs.
>>>
>>> Thanks
>>> Jingjing
>>>
>