RE: [PATCH v1] raw/ifpga: remove virtual device unplug operation

["Huang, Wei" <wei.huang@intel.com>]

> -----Original Message-----
> From: Thomas Monjalon <thomas@monjalon.net>
> Sent: Tuesday, March 21, 2023 18:30
> To: Huang, Wei <wei.huang@intel.com>
> Cc: dev@dpdk.org; david.marchand@redhat.com; stable@dpdk.org; Xu,
> Rosen <rosen.xu@intel.com>; Zhang, Tianfei <tianfei.zhang@intel.com>;
> Zhang, Qi Z <qi.z.zhang@intel.com>
> Subject: Re: [PATCH v1] raw/ifpga: remove virtual device unplug operation
> 
> 21/03/2023 09:41, Huang, Wei:
> > From: Thomas Monjalon <thomas@monjalon.net>
> > > 21/03/2023 01:11, Huang, Wei:
> > > > From: Thomas Monjalon <thomas@monjalon.net>
> > > > > 16/03/2023 21:44, Wei Huang:
> > > > > > VDEV bus has implemented cleanup() function to perform cleanup
> > > > > > for devices on the bus during eal_cleanup(), so there is no
> > > > > > need for ifpga driver to record virtual devices and unplug them.
> > > > >
> > > > > Why no need?
> > > > > If the application wants to explicitly remove a device, what happens?
> > > > >
> > > > >
> > > > EAL will output an error information "Cannot find plugged device (%s)".
> > >
> > > It does not look what we expect.
> > >
> > Let me clear it.
> > With this patch, no error information will be outputted.
> > Without this patch, error information will be outputted.
> > Because bus cleanup action will unplug virtual device, then ifpga PMD
> > unplug the virtual device which is already be cleanup,
> 
> Why ipfga unplug the device after the bus cleanup?
> I'm not following.
> 
The virtual device is created upon ifpga, if VDEV bus doesn't perform cleanup, ifpga has the responsibility to unplug these virtual devices.

> > bus->find_device() returns NULL,
> > EAL output "Cannot find plugged device (%s)\n" at line 302 in
> > eal_common_dev.c
> 
> Anyway, the good answer is not to completely remove the "remove"
> operation.
> 
If not to completely remove the "remove", the same virtual device will be unplug twice, is it reasonable?