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Date:   Thu, 5 Nov 2020 17:09:48 -0400
From:   Jason Gunthorpe <jgg@nvidia.com>
To:     Saeed Mahameed <saeed@kernel.org>
CC:     Leon Romanovsky <leon@kernel.org>,
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Subject: Re: [PATCH mlx5-next v1 05/11] net/mlx5: Register mlx5 devices to
 auxiliary virtual bus
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On Thu, Nov 05, 2020 at 12:59:20PM -0800, Saeed Mahameed wrote:

> 2. you can always load a driver without its underlying device existed.
> for example, you can load a pci device driver/module and it will load
> and wait for pci devices to pop up, the subsysetem infrastructure will
> match between drivers and devices and probe them.

Yes, this works fine with this design

> struct aux_driver mlx5_vpda_aux_driver {
> 
>       .name = "vdpa",
>        /* match this driver with mlx5_core devices */
>       .id_table = {"mlx5_core"}, 
>       .ops {
>             /* called before probe on actual aux mlx5_core device */
>            .is_supported(struct aux_device); 

This means module auto loading is impossible, we can't tell to load
the module until we load the module to call the is_supported code ..

Jason