Re: [dpdk-dev] [PATCH v2 3/3] eal: allow probing a device again

["Doherty, Declan" <declan.doherty@intel.com>]

On 28/09/2018 5:40 PM, Thomas Monjalon wrote:
> In the devargs syntax for device representors, it is possible to add
> several devices at once: -w dbdf,representor=[0-3]
> It will become a more frequent case when introducing wildcards
> and ranges in the new devargs syntax.
> 
> If a devargs string is provided for probing, and updated with a bigger
> range for a new probing, then we do not want it to fail because
> part of this range was already probed previously.
> There can be new ports to create from an existing rte_device.
> 
> That's why the checks for an already probed device
> are moved as PMD responsibility.
> Only the PMD knows the ports attached to one rte_device.
> 
> In the case of vdev, a global check is kept in insert_vdev(),
> assuming that a vdev will always have only one port.
> In the case of NXP buses, the probing is done only once (no hotplug),
> though a check is added at bus level for consistency.
> 
> As another consequence of being able to probe in several steps,
> the field rte_device.devargs must not be considered as a full
> representation of the rte_device, but only the latest probing args.
> Anyway, the field rte_device.devargs is used only for probing.
> 
> Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
> ---
...
> 

Hey Thomas, did you consider of adding a driver flags to the rte_driver 
structure which has a driver re-probe flag. If this flag is disabled by 
default, current drivers could be left unmodified and any new driver 
which want to support re-probing enable this flag and then support the 
functionality in there probe function. Then we could check this flag in 
the bus driver on making a call on whether to re-probe.

Declan