Re: [PATCH net v2] selftests: drv-net: Check if combined-count exists

[David Wei <dw@davidwei.uk>]

On 2025-02-26 10:19, Joe Damato wrote:
> Some drivers, like tg3, do not set combined-count:
> 
> $ ethtool -l enp4s0f1
> Channel parameters for enp4s0f1:
> Pre-set maximums:
> RX:		4
> TX:		4
> Other:		n/a
> Combined:	n/a
> Current hardware settings:
> RX:		4
> TX:		1
> Other:		n/a
> Combined:	n/a
> 
> In the case where combined-count is not set, the ethtool netlink code
> in the kernel elides the value and the code in the test:
> 
>   netnl.channels_get(...)
> 
> With a tg3 device, the returned dictionary looks like:
> 
> {'header': {'dev-index': 3, 'dev-name': 'enp4s0f1'},
>  'rx-max': 4,
>  'rx-count': 4,
>  'tx-max': 4,
>  'tx-count': 1}
> 
> Note that the key 'combined-count' is missing. As a result of this
> missing key the test raises an exception:
> 
>  # Exception|     if channels['combined-count'] == 0:
>  # Exception|        ~~~~~~~~^^^^^^^^^^^^^^^^^^
>  # Exception| KeyError: 'combined-count'
> 
> Change the test to check if 'combined-count' is a key in the dictionary
> first and if not assume that this means the driver has separate RX and
> TX queues.
> 
> With this change, the test now passes successfully on tg3 and mlx5
> (which does have a 'combined-count').
> 
> Fixes: 1cf270424218 ("net: selftest: add test for netdev netlink queue-get API")
> Signed-off-by: Joe Damato <jdamato@fastly.com>
> ---
>  v2:
>    - Simplify logic and reduce indentation as suggested by David Wei.
>      Retested on both tg3 and mlx5 and test passes as expected.
> 
>  v1: https://lore.kernel.org/lkml/20250225181455.224309-1-jdamato@fastly.com/

Thanks Joe.

Reviewed-by: David Wei <dw@davidwei.uk>