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Date:   Tue, 08 Sep 2020 19:28:45 -0700 (PDT)
Message-Id: <20200908.192845.1191873689940729972.davem@davemloft.net>
To:     grygorii.strashko@ti.com
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Subject: Re: [PATCH net-next v2 2/9] net: ethernet: ti: ale: add static
 configuration
From:   David Miller <davem@davemloft.net>
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From: Grygorii Strashko <grygorii.strashko@ti.com>
Date: Mon, 7 Sep 2020 17:31:36 +0300

> +	ale_dev_id = cpsw_ale_match_id(cpsw_ale_id_match, params->dev_id);
> +	if (ale_dev_id) {
> +		params->ale_entries = ale_dev_id->tbl_entries;
> +		params->major_ver_mask = ale_dev_id->major_ver_mask;
...
> -	if (!ale->params.major_ver_mask)
> -		ale->params.major_ver_mask = 0xff;

This is exactly the kind of change that causes regressions.

The default for the mask if no dev_id is found is now zero, whereas
before the default mask would be 0xff.

Please don't make changes like this, they are very risky.

In every step of these changes, existing behavior should be maintained
as precisely as possible.  Be as conservative as possible.