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Message-ID: <793a595932ea0adf7a72eeafb6ababdae8e21fc2.camel@sipsolutions.net>
Subject: Re: [PATCH 2/6] nl80211: add support to advertise driver's EHT
 capabilities
From:   Johannes Berg <johannes@sipsolutions.net>
To:     "Aloka Dixit (QUIC)" <quic_alokad@quicinc.com>
Cc:     "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
        "Vikram Kandukuri (QUIC)" <quic_vikram@quicinc.com>,
        "Jia Ding (QUIC)" <quic_jiad@quicinc.com>,
        "Karthikeyan Periyasamy (QUIC)" <quic_periyasa@quicinc.com>,
        "Muna Sinada (QUIC)" <quic_msinada@quicinc.com>,
        "Sriram R (QUIC)" <quic_srirrama@quicinc.com>,
        "Veerendranath Jakkam (QUIC)" <quic_vjakkam@quicinc.com>,
        Aloka Dixit <alokad@qti.qualcomm.com>
Date:   Thu, 10 Feb 2022 09:26:42 +0100
In-Reply-To: <DM8PR02MB795853BB4B1C71B20857D2D3FE2F9@DM8PR02MB7958.namprd02.prod.outlook.com>
References: <1640163883-12696-1-git-send-email-quic_vjakkam@quicinc.com>
         <1640163883-12696-3-git-send-email-quic_vjakkam@quicinc.com>
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On Thu, 2022-02-10 at 05:14 +0000, Aloka Dixit (QUIC) wrote:
> Hi Johannes,
> 
> Considering that 20MHz-only STA and one that supports other bandwidths will not occur at the same time,
> instead of a separate field for struct ieee80211_eht_mcs_nss_supp_20mhz_only inside struct ieee80211_eht_mcs_nss_supp, we can use a byte array as we added in here:
> https://patchwork.kernel.org/project/linux-wireless/patch/1640163883-12696-3-git-send-email-quic_vjakkam@quicinc.com/
> Instead of length field with dynamic allocation we can have an array of size 9 bytes.
> 

We did something like that in our patches:

https://patchwork.kernel.org/project/linux-wireless/patch/20220204230119.b0eeb527d761.I2413a37c8f7d2d6d638038a3d95360a3fce0114d@changeid/
https://patchwork.kernel.org/project/linux-wireless/patch/20220204230119.1ee92202ac30.Id30a3ef2844b296efbd5486fe1da9ca36a95c5cf@changeid/

Not overlapping wastes like 4 bytes of memory, I think I can live with
that, vs. the extra complexity? If you overlap you need another bit to
indicate which one you're using ...

johannes