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Date: Fri, 7 Mar 2025 17:33:45 +0800
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Subject: Re: [PATCH] ethdev: fix get_reg_info
To: Stephen Hemminger <stephen@networkplumber.org>, Thierry Herbelot
 <thierry.herbelot@6wind.com>
CC: <dev@dpdk.org>, Thomas Monjalon <thomas@monjalon.net>, <stable@dpdk.org>
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 <20250219104555.0bc2e0ff@hermes.local>
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On 2025/2/20 2:45, Stephen Hemminger wrote:
> On Tue, 18 Feb 2025 12:58:28 +0100
> Thierry Herbelot <thierry.herbelot@6wind.com> wrote:
> 
>> 'width' and 'offset' are input parameters when dumping the register
>> info of an Ethernet device. They should be copied in the new request
>> before calling the device callback function.
>>
>> Fixes: 083db2ed9e9 ('ethdev: add report of register names and filter')
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Thierry Herbelot <thierry.herbelot@6wind.com>
> 
> Why does the ethdev code create an on stack temporary variable.
> Looks like it only wants to make sure that names element is NULL.

It mainly for ABI compatibility.

The original solution is to add an ext API (rte_eth_dev_get_reg_info_ext) and deprecate the original API (rte_eth_dev_get_reg_info).

> 
> Really should be one function and when extended fields were added
> should have used API versioning.
> Probably too late now, although rte_eth_dev_get_reg_info_ext()
> is an experimental API.