RE: [EXT] [PATCH] compressdev: fix end of comp PMD list macro conflict

[Akhil Goyal <gakhil@marvell.com>]

> Subject: RE: [EXT] [PATCH] compressdev: fix end of comp PMD list macro
> conflict
> 
> > The "rte_compressdev_info_get()" function retrieves the contextual
> > information of a device.
> > The output structure "dev_info" contains a list of devices supported
> > capabilities for each supported algorithm.
> >
> > In this function description, it says the element after the last valid
> > element has op field set to "RTE_COMP_ALGO_LIST_END".
> > On the other hand, when this function used by
> > "rte_compressdev_capability_get()" function, it uses
> > "RTE_COMP_ALGO_UNSPECIFIED" as end of list as same as the
> > "RTE_COMP_END_OF_CAPABILITIES_LIST()".
> >
> > The mlx5 and qat PMDs use "RTE_COMP_ALGO_LIST_END" as the end of
> > capabilities list. When "rte_compressdev_capability_get()" function is
> > called with unsupported algorithm, it might read memory out of bound.
> >
> > This patch change the "rte_compressdev_info_get()" function description
> > to say using "RTE_COMP_ALGO_UNSPECIFIED" as the end of capabilities
> > list.
> > In addition, it moves both mlx5 and qat PMDs to use
> > "RTE_COMP_ALGO_UNSPECIFIED" through
> > "RTE_COMP_END_OF_CAPABILITIES_LIST()" macro.
> >
> > Fixes: 5d432f364078 ("compressdev: add device capabilities")
> > Fixes: 2d148597ce76 ("compress/qat: add gen-specific implementation")
> > Fixes: 384bac8d6555 ("compress/mlx5: add supported capabilities")
> > Cc: fiona.trahe@intel.com
> > Cc: roy.fan.zhang@intel.com
> > Cc: matan@nvidia.com
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Michael Baum <michaelba@nvidia.com>
> >
> > ---
> >
> > After this change, I'm not sure about the purpose of
> > "RTE_COMP_ALGO_LIST_END".
> > There is no any other use of it in DPDK code, and it isn't represent the
> > number of algorithms supported by the API since the
> > "RTE_COMP_ALGO_UNSPECIFIED" is part of the enum.
> >
> > Due to the compress API is experimental I think the
> > "RTE_COMP_ALGO_LIST_END" can be removed.
> >
> +1 to remove the list end enums. This will also help in avoiding ABI breakage
> When we make this lib as stable.

Even RTE_COMP_HASH_ALGO_LIST_END can also be removed.
It is not used anywhere.