From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pegase2.c-s.fr (pegase2.c-s.fr [93.17.235.10]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 749D9A937 for ; Sat, 8 Nov 2025 11:20:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=93.17.235.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762600837; cv=none; b=dM6/jqdFf5u01zc70puQr264MnVEOgyQYXYvNIOBaN6dJoEUXSnMPdoCBtdmR1sZZmRqSBMA3cTklMSfDg4BmUk1BOpqUsKtgrSIRLhgSV6eA2TBXtp0G+4LrAs9HQvddOV2GstKf8geVMXzhQJq5jX2aF+37PndtAqk+iFWZI4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762600837; c=relaxed/simple; bh=LzGDqy90kyLrU0YnNZy0sotPQtZDQuSJSoD37aZLUL8=; h=Message-ID:Date:MIME-Version:Subject:From:To:Cc:References: In-Reply-To:Content-Type; b=hJg00rQhm3ofDVqqUQSZlKbiYQPE6t5EfU93MVvxr0P7jB8p2naYnlMxDFhJXfK4pBr7dumhxhTcjUOjkUPBRSnFeHW9nBNWA5dIffy7vZ3DoG+AlEi7txMDx0m8lCex9AdV+csoPH6COfuKT2NVRBfXkM8ENttuL3EilkY0I+U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=csgroup.eu; spf=pass smtp.mailfrom=csgroup.eu; arc=none smtp.client-ip=93.17.235.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=csgroup.eu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=csgroup.eu Received: from localhost (mailhub4.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4d3YHH1lmCz9sS7; Sat, 8 Nov 2025 12:14:51 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id wykipwaqZfoa; Sat, 8 Nov 2025 12:14:51 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4d3YHH0rPtz9sRy; Sat, 8 Nov 2025 12:14:51 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 0AEC48B765; Sat, 8 Nov 2025 12:14:51 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id R_iuyd3THbw8; Sat, 8 Nov 2025 12:14:50 +0100 (CET) Received: from [192.168.235.99] (unknown [192.168.235.99]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 9BD968B764; Sat, 8 Nov 2025 12:14:50 +0100 (CET) Message-ID: Date: Sat, 8 Nov 2025 12:14:50 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] eeprom: at25: convert to spi-mem API From: Christophe Leroy To: "Sverdlin, Alexander" , "gregkh@linuxfoundation.org" Cc: "hui.wang@canonical.com" , "mwalle@kernel.org" , "linux-kernel@vger.kernel.org" , "florent.trinh-thai@cs-soprasteria.com" , "arnd@arndb.de" References: <20250702222823.864803-1-alexander.sverdlin@siemens.com> <638496dd-ec60-4e53-bad7-eb657f67d580@csgroup.eu> <2025110513-manliness-repayment-d005@gregkh> Content-Language: fr-FR In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Hi Again, Le 08/11/2025 à 11:05, Christophe Leroy a écrit : > Hi Alexander, > > Now I'm trying to understand why the problem surfaced with commit > 8ad6249c51d0 ("eeprom: at25: convert to spi-mem API") > The reason why it was not a problem before was that the transfer was done into of->prealloc_buf (fs/kernfs/file.c) which is a kmalloc() with size (PAGE_SIZE + 1). Following the rework of at25 it now goes into the bounce buffer which is allocated with the exact size of the transfer. Why do we need an intermediate bounce buffer now, why can't of->prealloc_buf be used directly as before ? Christophe