From: "Qiu, Michael" <michael.qiu@intel.com>
To: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>,
"Zhang, Helin" <helin.zhang@intel.com>,
"Lu, Wenzhuo" <wenzhuo.lu@intel.com>,
"dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH v2] ixgbe: Fix disable interrupt twice
Date: Fri, 19 Feb 2016 08:07:20 +0000 [thread overview]
Message-ID: <533710CFB86FA344BFBF2D6802E6028622F44907@SHSMSX101.ccr.corp.intel.com> (raw)
In-Reply-To: <2601191342CEEE43887BDE71AB97725836B02321@irsmsx105.ger.corp.intel.com>
On 2016/2/2 19:03, Ananyev, Konstantin wrote:
>
[...]
>>>> I don't think i40e miss it, because it not the right please to disable interrupt.
>>>> because all interrupts are enabled in init stage.
>>>>
>>>> Actually, ixgbe enable the interrupt in init stage, but in dev_start, it disable it
>>>> first and re-enable, so it just the same with doing nothing about interrupt.
>>>>
>>>> Just think below:
>>>>
>>>> 1. start the port.(interrupt already enabled in init stage, disable -->
>>>> re-enable)
>>>> 2. stop the port.(disable interrupt)
>>>> 3. start port again(Try to disable, but failed, already disabled)
>>>>
>>>> Would you think the code has issue?
>>> [Zhang, Helin] in ixgbe PMD, it can be seen that uninit() calls dev_close(),
>>> which calls dev_stop(). So I think the disabling can be done only in dev_stop().
>>> All others can make use of dev_stop to disable the interrupt.
>> As I said, if it is in dev_stop, it will has issue when dev_start -->
>> dev_stop --> dev_start, this also could applied in i40e and fm10k. If
>> you want to put it in dev_stop, better to remove enable interrupts in
>> init stage, and only put it in dev_start.
> We can't remove enabling interrupt at init stage and put it only in dev_start().
> That means PF couldn't handle interrupts from VF till dev_start() will be executed on PF
> - which could never happen.
> For same reason we can't disable all interrupts in dev_stop().
> See: http://dpdk.org/ml/archives/dev/2015-November/027238.html
Hi, Konstantin
Yes, you are right.
So the only way to fix this issue should remove it in dev_stop(), and
left it in uinit() stage, which my patch does.
Am I right?
Thanks,
Michael
> Konstantin
>
>> Thanks,
>> Michael
>>> Regards,
>>> Helin
>>>
>>>> Thanks,
>>>> Michael
>>>>
>>>>> Maybe we can follow fm10k's style.
>>>>>
>>>>>> On other hand, if we remove it in dev_stop, any side effect? In ixgbe
>>>>>> start, it will always disable it first and then re-enable it, so it's safe.
>>>>> I think you mean we can disable intr anyway even if it has been disabled.
>>>> Actually, we couldn't, DPDK call VFIO ioctl to kernel to disable interrupts, and
>>>> if we try disable twice, it will return and error.
>>>> That's why I mean we need a flag to show the interrupts stats. If it already
>>>> disabled, we do not need call in to kernel. just return and give a warning
>>>> message.
>>>>
>>>> Thanks,
>>>> Michael
>>>>
>>>>> Sounds more like why we don't
>>>>> need this patch :)
>>>>>
>>>>>> Thanks,
>>>>>> Michael
>
next prev parent reply other threads:[~2016-02-19 8:07 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-29 5:51 [dpdk-dev] [PATCH] " Michael Qiu
2016-01-29 5:58 ` [dpdk-dev] [PATCH v2] " Michael Qiu
2016-01-29 8:07 ` Lu, Wenzhuo
2016-02-01 8:05 ` Qiu, Michael
2016-02-02 1:03 ` Lu, Wenzhuo
2016-02-02 2:06 ` Qiu, Michael
2016-02-02 2:14 ` Zhang, Helin
2016-02-02 2:57 ` Qiu, Michael
2016-02-02 3:07 ` Zhang, Helin
2016-02-02 3:15 ` Qiu, Michael
2016-02-02 11:03 ` Ananyev, Konstantin
2016-02-19 8:07 ` Qiu, Michael [this message]
2016-02-19 15:14 ` Ananyev, Konstantin
2016-02-02 2:26 ` Lu, Wenzhuo
2016-02-23 2:10 ` Zhang, Helin
2016-02-26 14:39 ` Bruce Richardson
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