Re: [PATCH] i40e: don't enable and init FCOE by default when do PF reset

[ethan zhao <ethan.zhao@oracle.com>]

Vasu,

   What' your idea about the v2, any suggestion ?  Jeff is looking 
forward to see it.

Thanks,
Ethan


On 2015/1/16 22:47, Jeff Kirsher wrote:
> On Fri, 2015-01-16 at 09:48 +0800, ethan zhao wrote:
>> Vasu,
>>
>>      OK, disable FCOE as default configuration as a temporary step to
>> make it  work.
> Sounds like I should expect a v2 coming, correct?
>
>>
>> Thanks,
>> Ethan
>>
>> On 2015/1/16 7:45, Dev, Vasu wrote:
>>>> -----Original Message-----
>>>> From: ethan zhao [mailto:ethan.zhao@oracle.com]
>>>> Sent: Tuesday, January 13, 2015 6:41 PM
>>>> To: Dev, Vasu
>>>> Cc: Ethan Zhao; Ronciak, John; Kirsher, Jeffrey T; Brandeburg, Jesse; Allan,
>>>> Bruce W; Wyborny, Carolyn; Skidmore, Donald C; Rose, Gregory V; Vick,
>>>> Matthew; Williams, Mitch A; Parikh, Neerav; Linux NICS; e1000-
>>>> devel@lists.sourceforge.net; netdev@vger.kernel.org; linux-
>>>> kernel@vger.kernel.org; brian.maly@oracle.com
>>>> Subject: Re: [PATCH] i40e: don't enable and init FCOE by default when do PF
>>>> reset
>>>>
>>>> Vasu,
>>>>
>>>> On 2015/1/14 3:38, Dev, Vasu wrote:
>>>>>> -----Original Message-----
>>>>>>>>> diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c
>>>>>>>>> b/drivers/net/ethernet/intel/i40e/i40e_main.c
>>>>>>>>> index a5f2660..a2572cc 100644
>>>>>>>>> --- a/drivers/net/ethernet/intel/i40e/i40e_main.c
>>>>>>>>> +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
>>>>>>>>> @@ -6180,9 +6180,12 @@ static void i40e_reset_and_rebuild(struct
>>>>>>>>> i40e_pf *pf, bool reinit)
>>>>>>>>>        }
>>>>>>>>>     #endif /* CONFIG_I40E_DCB */
>>>>>>>>>     #ifdef I40E_FCOE
>>>>>>>>> -   ret = i40e_init_pf_fcoe(pf);
>>>>>>>>> -   if (ret)
>>>>>>>>> -           dev_info(&pf->pdev->dev, "init_pf_fcoe failed: %d\n", ret);
>>>>>>>>> +   if (pf->flags & I40E_FLAG_FCOE_ENABLED) {
>>>>>>>>> +           ret = i40e_init_pf_fcoe(pf);
>>>>>>> Calling i40e_init_pf_fcoe() here conflicts with its
>>>>>> I40E_FLAG_FCOE_ENABLED pre-condition since
>>>> I40E_FLAG_FCOE_ENABLED is
>>>>>> set by very same i40e_init_pf_fcoe(), in turn i40e_init_pf_fcoe()
>>>>>> will never get called.
>>>>>>
>>>>>> I don't think so,  here ,i40e_reset_and_rebuild()  is not the only
>>>>>> and the first place that  i40e_init_pf_fcoe() is called, see
>>>>>> i40e_probe(), that is the first chance.
>>>>>>
>>>>>> i40e_probe()
>>>>>> -->i40e_sw_init()
>>>>>>         -->i40e_init_pf_fcoe()
>>>>>>
>>>>>> And the I40E_FLAG_FCOE_ENABLED is possible be set by
>>>>>> i40e_fcoe_enable() or i40e_fcoe_disable() interface before the reset
>>>>>> action is to be done.
>>>>>>
>>>>> It is set by i40e_init_pf_fcoe() and you are right that the modified call flow
>>>> by your patch won't impact setting of I40E_FLAG_FCOE_ENABLED anyway
>>>> which could have prevented calling i40e_init_pf_fcoe() as I described above,
>>>> so this is not an issue with the patch.
>>>>>> BTW, the reason I post this patch is that we hit a bug, after setup
>>>>>> vlan, the PF is enabled to FCOE.
>>>>>>
>>>>> Then that BUG would still remain un-fixed and calling i40e_init_pf_fcoe()
>>>> under I40E_FLAG_FCOE_ENABLED  flag really won't affect call flow to fix
>>>> anything. I mean I40E_FLAG_FCOE_ENABLED  condition will be true with "pf-
>>>>> hw.func_caps.fcoe == true" and otherwise calling i40e_init_pf_fcoe() simply
>>>> returns back early on after checking "pf->hw.func_caps.fcoe == false", so
>>>> how that bug is fixed here by added I40E_FLAG_FCOE_ENABLED  condition ?
>>>> What is the bug ?
>>>>     The func_caps.fcoe is assigned by following call path, under our test
>>>> environment,
>>>>
>>>>     i40e_probe()
>>>>      ->i40e_get_capabilities()
>>>>         ->i40e_aq_discover_capabilities()
>>>>            ->i40e_parse_discover_capabilities()
>>>>
>>>>     Or
>>>>
>>>>     i40e_reset_and_rebuild()
>>>>      ->i40e_get_capabilities()
>>>>        ->i40e_aq_discover_capabilities()
>>>>          ->i40e_parse_discover_capabilities()
>>>>
>>>>     Under our test environment, the "pf->hw.func_caps.fcoe" is true. so if
>>>> i40e_reset_and_rebuild() is called for VLAN setup, ethtool diagnostic test.
>>>>     And then i40e_init_pf_fcoe() is to be called,
>>>>
>>>>     While if (!pf->hw.func_caps.fcoe) wouldn't return,
>>>>
>>> I said it would return with "pf->hw.func_caps.fcoe == false" in my last response, more details below.
>>>
>>>>     So  pf->flags is set to I40E_FLAG_FCOE_ENABLED.
>>>>
>>>>     With my patch,  i40e_init_pf_fcoe() is only called after
>>>> I40E_FLAG_FCOE_ENABLED is set before reset.
>>>>
>>>> Enable FCOE in i40e_probe() or not is another issue.
>>>>
>>> Nope since both cases we should do i40e_init_pf_fcoe() or don't based on fcoe cap true or false.
>>>
>>> I don't have much to add as I described before with the your patch that "calling i40e_init_pf_fcoe() under I40E_FLAG_FCOE_ENABLED  flag really won't affect call flow to fix anything. I mean I40E_FLAG_FCOE_ENABLED  condition will be true with "pf->hw.func_caps.fcoe == true" and otherwise calling i40e_init_pf_fcoe() simply returns back early on after checking "pf->hw.func_caps.fcoe == false".
>>>
>>> May be I'm missing something, I guess next either go with CONFIG_I40E_FCOE disable as I suggested before and now it in upstream kernel or we can have further off list discussion to fix the issue you are trying to fix with the patch.
>>>
>>> Thanks,
>>> Vasu
>>>
>>>> Thanks,
>>>> Ethan
>>>>
>>>>
>>>>>>> Jeff Kirsher should be getting out a patch queued by me which adds
>>>>>> I40E_FCoE Kbuild option, in that FCoE is disabled by default and
>>>>>> user could enable FCoE only if needed, that patch would do same of
>>>>>> skipping
>>>>>> i40e_init_pf_fcoe() whether FCoE capability in device enabled or not
>>>>>> in default config.
>>>>>> The following patch will not fix the above issue -- configuration of
>>>>>> PF will be changed via reset.
>>>>>> How about the FCOE is configured and disabled by  i40e_fcoe_disable()
>>>>>> , then reset happens ?
>>>>>>
>>>>> May be but if the BUG is due to FCoE being enabled then having it disabled
>>>> in config will avoid the bug for non FCoE config option and once bug is
>>>> understood then that has to be fixed for FCoE enabled config also as I asked
>>>> above.
>>>>> Thanks Ethan for detailed response.
>>>>> Vasu
>>>>>
>>>>>>>    From patchwork Wed Oct  2 23:26:08 2013
>>>>>>> Content-Type: text/plain; charset="utf-8"
>>>>>>> MIME-Version: 1.0
>>>>>>> Content-Transfer-Encoding: 7bit
>>>>>>> Subject: [net] i40e: adds FCoE configure option
>>>>>>> Date: Thu, 03 Oct 2013 07:26:08 -0000
>>>>>>> From: Vasu Dev <vasu.dev@intel.com>
>>>>>>> X-Patchwork-Id: 11797
>>>>>>>
>>>>>>> Adds FCoE config option I40E_FCOE, so that FCoE can be enabled as
>>>>>>> needed but otherwise have it disabled by default.
>>>>>>>
>>>>>>> This also eliminate multiple FCoE config checks, instead now just
>>>>>>> one config check for CONFIG_I40E_FCOE.
>>>>>>>
>>>>>>> The I40E FCoE was added with 3.17 kernel and therefore this patch
>>>>>>> shall be applied to stable 3.17 kernel also.
>>>>>>>
>>>>>>> CC: <stable@vger.kernel.org>
>>>>>>> Signed-off-by: Vasu Dev <vasu.dev@intel.com>
>>>>>>> Tested-by: Jim Young <jamesx.m.young@intel.com>
>>>>>>>
>>>>>>> ---
>>>>>>> drivers/net/ethernet/intel/Kconfig           |   11 +++++++++++
>>>>>>>     drivers/net/ethernet/intel/i40e/Makefile     |    2 +-
>>>>>>>     drivers/net/ethernet/intel/i40e/i40e_osdep.h |    4 ++--
>>>>>>>     3 files changed, 14 insertions(+), 3 deletions(-)
>>>>>>>
>>>>>>> diff --git a/drivers/net/ethernet/intel/Kconfig
>>>>>>> b/drivers/net/ethernet/intel/Kconfig
>>>>>>> index 5b8300a..4d61ef5 100644
>>>>>>> --- a/drivers/net/ethernet/intel/Kconfig
>>>>>>> +++ b/drivers/net/ethernet/intel/Kconfig
>>>>>>> @@ -281,6 +281,17 @@ config I40E_DCB
>>>>>>>
>>>>>>>              If unsure, say N.
>>>>>>>
>>>>>>> +config I40E_FCOE
>>>>>>> +       bool "Fibre Channel over Ethernet (FCoE)"
>>>>>>> +       default n
>>>>>>> +       depends on I40E && DCB && FCOE
>>>>>>> +       ---help---
>>>>>>> +         Say Y here if you want to use Fibre Channel over Ethernet (FCoE)
>>>>>>> +         in the driver. This will create new netdev for exclusive FCoE
>>>>>>> +         use with XL710 FCoE offloads enabled.
>>>>>>> +
>>>>>>> +         If unsure, say N.
>>>>>>> +
>>>>>>>     config I40EVF
>>>>>>>            tristate "Intel(R) XL710 X710 Virtual Function Ethernet support"
>>>>>>>            depends on PCI_MSI
>>>>>>> diff --git a/drivers/net/ethernet/intel/i40e/Makefile
>>>>>>> b/drivers/net/ethernet/intel/i40e/Makefile
>>>>>>> index 4b94ddb..c405819 100644
>>>>>>> --- a/drivers/net/ethernet/intel/i40e/Makefile
>>>>>>> +++ b/drivers/net/ethernet/intel/i40e/Makefile
>>>>>>> @@ -44,4 +44,4 @@ i40e-objs := i40e_main.o \
>>>>>>>            i40e_virtchnl_pf.o
>>>>>>>
>>>>>>>     i40e-$(CONFIG_I40E_DCB) += i40e_dcb.o i40e_dcb_nl.o
>>>>>>> -i40e-$(CONFIG_FCOE:m=y) += i40e_fcoe.o
>>>>>>> +i40e-$(CONFIG_I40E_FCOE) += i40e_fcoe.o
>>>>>>> diff --git a/drivers/net/ethernet/intel/i40e/i40e_osdep.h
>>>>>>> b/drivers/net/ethernet/intel/i40e/i40e_osdep.h
>>>>>>> index 045b5c4..ad802dd 100644
>>>>>>> --- a/drivers/net/ethernet/intel/i40e/i40e_osdep.h
>>>>>>> +++ b/drivers/net/ethernet/intel/i40e/i40e_osdep.h
>>>>>>> @@ -78,7 +78,7 @@ do {                                                            \
>>>>>>>     } while (0)
>>>>>>>
>>>>>>>     typedef enum i40e_status_code i40e_status; -#if
>>>>>>> defined(CONFIG_FCOE)
>>>>>>> || defined(CONFIG_FCOE_MODULE)
>>>>>>> +#ifdef CONFIG_I40E_FCOE
>>>>>>>     #define I40E_FCOE
>>>>>>> -#endif /* CONFIG_FCOE or CONFIG_FCOE_MODULE */
>>>>>>> +#endif
>>>>>>>     #endif /* _I40E_OSDEP_H_ */
>>>>>>>
>>>>>>>>> +           if (ret)
>>>>>>>>> +                   dev_info(&pf->pdev->dev,
>>>>>>>>> +                            "init_pf_fcoe failed: %d\n", ret);
>>>>>>>>> +   }
>>>>>>>>>
>>>>>>>>>     #endif
>>>>>>>>>        /* do basic switch setup */
>>>>>>>>> --
>>>>>>>>> 1.8.3.1
>>>>>> Thanks,
>>>>>> Ethan
>