Re: [dpdk-dev] [PATCH] app/testpmd: change port detach interface

[Nithin Dabilpuram <nithind1988@gmail.com>]

Hi Thomas,
On Tue, May 14, 2019 at 05:39:30PM +0200, Thomas Monjalon wrote:
> Hi,
> 
> 13/05/2019 13:21, Nithin Dabilpuram:
> > With the latest published interface of
> > rte_eal_hotplug_[add,remove](), and rte_eth_dev_close(),
> > rte_eth_dev_close() would cleanup all the data structures of
> > port's eth dev leaving the device common resource intact
> > if RTE_ETH_DEV_CLOSE_REMOVE is set in dev flags.
> > So "port detach" (~hotplug remove) should be able to work,
> > with device identifier like "port attach" as eth_dev could have
> > been closed already and rte_eth_devices[port_id] reused.
> 
> "port attach" uses devargs as identifier because there
> is no port id before creating it. But "detach port" uses
> logically the port id to close.
But if "port close" was already called on that port,
eth_dev->state would be set as RTE_ETH_DEV_UNUSED and
that port id could be reused.
So after "port close" if we call "port detach", isn't it
incorrect to use the same port id ?
> 
> > This change alters "port detach" cmdline interface to
> > work with device identifier like "port attach".
> 
> The word "port" means an ethdev port, so it should be
> referenced with a port id.
> If you want to close an EAL rte_device, then you should
> rename the command.
> But testpmd purpose should be to work with ethdev ports only.
Renaming the command to "detach <identifier>" ?
> 
> PS: Please remind that a device can have multiple ports.
> 
>