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References: <20211104010548.1107405-1-benl@squareup.com> <20211104010548.1107405-2-benl@squareup.com>
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From:   Loic Poulain <loic.poulain@linaro.org>
Date:   Thu, 4 Nov 2021 19:57:02 +0100
Message-ID: <CAMZdPi8SnET8x0CBOyzSNcXroy=ctb_k-qE=bqpx_8027vVTTA@mail.gmail.com>
Subject: Re: [PATCH v3 1/2] wcn36xx: populate band before determining rate on RX
To:     Benjamin Li <benl@squareup.com>
Cc:     Kalle Valo <kvalo@codeaurora.org>,
        "Bryan O'Donoghue" <bryan.odonoghue@linaro.org>,
        linux-arm-msm@vger.kernel.org,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>, wcn36xx@lists.infradead.org,
        linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
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On Thu, 4 Nov 2021 at 02:05, Benjamin Li <benl@squareup.com> wrote:
>
> status.band is used in determination of status.rate -- for 5GHz on legacy
> rates there is a linear shift between the BD descriptor's rate field and
> the wcn36xx driver's rate table (wcn_5ghz_rates).
>
> We have a special clause to populate status.band for hardware scan offload
> frames. However, this block occurs after status.rate is already populated.
> Correctly handle this dependency by moving the band block before the rate
> block.
>
> This patch addresses kernel warnings & missing scan results for 5GHz APs
> that send their beacons/probe responses at the higher four legacy rates
> (24-54 Mbps), when using hardware scan offload:
>
>   ------------[ cut here ]------------
>   WARNING: CPU: 0 PID: 0 at net/mac80211/rx.c:4532 ieee80211_rx_napi+0x744/0x8d8
>   Modules linked in: wcn36xx [...]
>   CPU: 0 PID: 0 Comm: swapper/0 Tainted: G        W         4.19.107-g73909fa #1
>   Hardware name: Square, Inc. T2 (all variants) (DT)
>   Call trace:
>   dump_backtrace+0x0/0x148
>   show_stack+0x14/0x1c
>   dump_stack+0xb8/0xf0
>   __warn+0x2ac/0x2d8
>   warn_slowpath_null+0x44/0x54
>   ieee80211_rx_napi+0x744/0x8d8
>   ieee80211_tasklet_handler+0xa4/0xe0
>   tasklet_action_common+0xe0/0x118
>   tasklet_action+0x20/0x28
>   __do_softirq+0x108/0x1ec
>   irq_exit+0xd4/0xd8
>   __handle_domain_irq+0x84/0xbc
>   gic_handle_irq+0x4c/0xb8
>   el1_irq+0xe8/0x190
>   lpm_cpuidle_enter+0x220/0x260
>   cpuidle_enter_state+0x114/0x1c0
>   cpuidle_enter+0x34/0x48
>   do_idle+0x150/0x268
>   cpu_startup_entry+0x20/0x24
>   rest_init+0xd4/0xe0
>   start_kernel+0x398/0x430
>   ---[ end trace ae28cb759352b403 ]---
>
> Fixes: 8a27ca394782 ("wcn36xx: Correct band/freq reporting on RX")
> Signed-off-by: Benjamin Li <benl@squareup.com>

Tested-by: Loic Poulain <loic.poulain@linaro.org>