Re: [dpdk-dev] [PATCH] igb_uio: remove device reset in open

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 10/26/2017 2:28 AM, Tan, Jianfeng wrote:
> Hi Rasesh,
> 
> 
> On 10/26/2017 7:43 AM, Mody, Rasesh wrote:
>> Hi Ferruh,
>>
>>> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Ferruh Yigit
>>> Sent: Friday, October 20, 2017 9:58 AM
>>>
>>> On 10/20/2017 9:55 AM, Ferruh Yigit wrote:
>>>> Remove device reset during application start, the reset for
>>>> application exit still there.
>>>>
>>>> Reset in open removed because of following comments:
>>>> 1- Device reset not completed when VF driver loaded, which cause VF PMD
>>>>     initialization error.
>>>>     Adding delay can solve the issue but will increase driver load time.
>>>>
>>>> 2- Reset will be issues all devices unconditionally, not very efficient
>>>>     way.
>>>>
>>>> Fixes: b58eedfc7dd5 ("igb_uio: issue FLR during open and release of
>>>> device file")
>>>> Cc: stable@dpdk.org
>>>>
>>>> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
>>> Hi Jingjing, Shijith, Gregory, Harish,
>>>
>>> Can you please test this on top of current master (which has already Jingjin's
>>> fix) ?
>> The original FLR change during igb_uio open()/release() in DPDK17.08 also impacts BNX2X PMD and it exhibits the issues with bare metal testing.
>>   
>> Now, we tested this change for BNX2X PMD using latest dpdk, which has this fix where FLR is invoked only in the release(). 

Good to hear this fixed the problem.

>> However, we ran into an issue when trying to reload the testpmd application in quick succession. The pci reset, called during the igb_uio release() operation, is taking longer time and adapter is still doing the FLR when we relaunch the application. We see this behavior with bare metal testing.
> 
> If we don't reset that device, it will continue working which is a more 
> serious issue IMO.

+1

> How long does it take to reset BTW?

I was wondering same thing.

> 
> Thanks,
> Jianfeng
>