Received-SPF: pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH v3 2/9] brcmfmac: firmware: Allocate space for default
 boardrev in nvram
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     Kalle Valo <kvalo@codeaurora.org>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Len Brown <lenb@kernel.org>,
        Arend van Spriel <aspriel@gmail.com>,
        Franky Lin <franky.lin@broadcom.com>,
        Hante Meuleman <hante.meuleman@broadcom.com>,
        Chi-hsien Lin <chi-hsien.lin@infineon.com>,
        Wright Feng <wright.feng@infineon.com>,
        Dmitry Osipenko <digetx@gmail.com>,
        Sven Peter <sven@svenpeter.dev>,
        Alyssa Rosenzweig <alyssa@rosenzweig.io>,
        Mark Kettenis <kettenis@openbsd.org>,
        =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= <zajec5@gmail.com>,
        Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>,
        Linus Walleij <linus.walleij@linaro.org>,
        Hans de Goede <hdegoede@redhat.com>,
        "John W. Linville" <linville@tuxdriver.com>,
        "brian m. carlson" <sandals@crustytoothpaste.net>,
        "open list:TI WILINK WIRELES..." <linux-wireless@vger.kernel.org>,
        netdev <netdev@vger.kernel.org>,
        devicetree <devicetree@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
        "open list:BROADCOM BRCM80211 IEEE802.11n WIRELESS DRIVER" 
        <brcm80211-dev-list.pdl@broadcom.com>,
        SHA-cyfmac-dev-list@infineon.com
References: <20220117142919.207370-1-marcan@marcan.st>
 <20220117142919.207370-3-marcan@marcan.st>
 <CAHp75VdZG4n1QySXyM+w1gJOWzq5Ng-Ym8dL1sSC_MLP2hqxAw@mail.gmail.com>
From:   Hector Martin <marcan@marcan.st>
Message-ID: <af02e786-873e-50e3-473b-3d57e3c52be3@marcan.st>
Date:   Thu, 20 Jan 2022 15:08:36 +0900
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.13.0
MIME-Version: 1.0
In-Reply-To: <CAHp75VdZG4n1QySXyM+w1gJOWzq5Ng-Ym8dL1sSC_MLP2hqxAw@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Language: es-ES
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 20/01/2022 06.35, Andy Shevchenko wrote:
> On Mon, Jan 17, 2022 at 4:30 PM Hector Martin <marcan@marcan.st> wrote:
>>
>> If boardrev is missing from the NVRAM we add a default one, but this
>> might need more space in the output buffer than was allocated. Ensure
>> we have enough padding for this in the buffer.
> 
> Do you know this ahead (before allocation happens)?
> If yes, the size change should happen conditionally.
> 
> Alternatively, krealloc() may be used.

We don't know if we will have to add a boardrev until we find it's
missing. The buffer is already oversized anyway, as its size is computed
based on the input NVRAM size, while comments and such will be removed.
This is just increasing the existing worst-case allocation to properly
account for the true worst-case case.

I don't think trying to keep the buffer perfectly sized buys us anything
here, since it will be freed after download anyway. There's no point in
saving a few bytes of memory in the interim.

-- 
Hector Martin (marcan@marcan.st)
Public Key: https://mrcn.st/pub