Re: [dpdk-dev] [EXT] Re: [PATCH 2/2] net/qede: restore Tx queue setup

[Rasesh Mody <rmody@marvell.com>]

Hi,

>From: Thomas Monjalon <thomas@monjalon.net>
>Sent: Tuesday, May 05, 2020 2:15 AM
>
>05/05/2020 10:59, Ferruh Yigit:
>> On 5/5/2020 7:44 AM, Jerin Jacob wrote:
>> > On Tue, May 5, 2020 at 8:39 AM Rasesh Mody <rmody@marvell.com>
>wrote:
>> >>
>> >> Some applications do not explicitly restore Tx queues setup during
>> >> port re-configuration. This patch adds changes to check for
>> >> released Tx queues and restore the setup if application doesn't
>> >> explicitly does that.
>> >
>> > +ethdev maintainers.
>> >
>> > I think, Ideally, the fix should be in common code if we need to
>> > support such applications.
>>
>> Is this a case application re-configures to increase the number of
>> queues but doesn't setup new queues?
>> If so this looks like application error and application should be
>> fixed instead of recover this in the ethdev.
>
>+1
>

This is a case of KNI application performing device re-configuration to change MTU. The application explicitly calls Rx queue setup, however doesn't call Tx queue setup. When MTU for KNI interface is changed it runs into a segfault when trying to start Tx queues.
Some other applications make use of rte_eth_dev_set_mtu() ethdev op, which looks to be cleaner approach.

Thanks!
-Rasesh