linux-kernel - Re: [PATCH net-next] ath10k: fix RX of frames with broken FCS in monitor mode

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Message-ID: <6ca7e338-d14d-49f6-f51c-600856b59767@candelatech.com>
Date:   Thu, 7 Nov 2019 07:24:06 -0800
From:   Ben Greear <greearb@...delatech.com>
To:     Linus Lüssing <linus.luessing@...3.blue>
Cc:     Linus Lüssing <ll@...onwunderlich.de>,
        ath10k@...ts.infradead.org, Kalle Valo <kvalo@...eaurora.org>,
        "David S . Miller" <davem@...emloft.net>,
        Simon Wunderlich <sw@...onwunderlich.de>,
        linux-wireless@...r.kernel.org, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH net-next] ath10k: fix RX of frames with broken FCS in
 monitor mode



On 11/07/2019 06:03 AM, Linus Lüssing wrote:
> On Tue, Nov 05, 2019 at 09:19:20AM -0800, Ben Greear wrote:
>> Thanks for adding the counter.  Since it us u32, I doubt you need the spin lock
>> below?
>
> Ok, I can remove the spin-lock.
>
> Just for clarification though, if I recall correctly then an increment operator
> is not guaranteed to work atomically. But you think it's unlikely
> to race with a concurrent ++ and therefore it's fine for just a debug counter?
> (and if it were racing, it'd just be a missed +1)

I think it is fine to be off-by-one, and u32 is atomic so you would never read a really
weird number, like you can if u64 is non-atomically being incremented.

Thanks,
Ben


-- 
Ben Greear <greearb@...delatech.com>
Candela Technologies Inc  http://www.candelatech.com