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

From: Jeff Kirsher
Date: Fri Jan 16 2015 - 09:47:17 EST


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@xxxxxxxxxx]
> >> 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@xxxxxxxxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-
> >> kernel@xxxxxxxxxxxxxxx; brian.maly@xxxxxxxxxx
> >> 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@xxxxxxxxx>
> >>>>> 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@xxxxxxxxxxxxxxx>
> >>>>> Signed-off-by: Vasu Dev <vasu.dev@xxxxxxxxx>
> >>>>> Tested-by: Jim Young <jamesx.m.young@xxxxxxxxx>
> >>>>>
> >>>>> ---
> >>>>> 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
>


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