From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay4-d.mail.gandi.net (relay4-d.mail.gandi.net [217.70.183.196]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F156E3E462; Mon, 6 May 2024 07:17:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.196 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714979874; cv=none; b=CBn2tVLy5kjZt61LTj6nKTQAQWsEybdNbUm733XjSnMXHE0caU2vUzc0Ck1uIogfD0euV3z/1JcR3//koOSRvtOYa2qJLsF844D5Lcet2GJL2ScQd2z4DbLIxzQ+sl2rda72nMpqLYnMg+TV/WuZhGffgreY/Ynw2DRKP19kVdY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714979874; c=relaxed/simple; bh=R6TiNw7b/eFI6QFHmACKnQ+Lmgs4hhHYmLO5oH7iZKc=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=bxrCcyeJH+cutwSrhm7MzQF6DAYTifCQCKPpKJe0vwreMfZupoSzGUT7bYDY/T1tB1HVcFP0RMYOzyv+wrJJ7XbeeK9IIfNsQlWfiScmIhSZgal5vrVCt3Epymha5s+emBHnguqzC6Cz0LhX2a2MS/NJIKtb6VUhE+ShgUo4q0Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=lzRZVz0G; arc=none smtp.client-ip=217.70.183.196 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="lzRZVz0G" Received: by mail.gandi.net (Postfix) with ESMTPSA id 49146E0006; Mon, 6 May 2024 07:17:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1714979870; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=R6TiNw7b/eFI6QFHmACKnQ+Lmgs4hhHYmLO5oH7iZKc=; b=lzRZVz0GLJ74p8N/yXNAbwpykF1XLxu8H/V9Js14qzM39RB9kJCAuDpmQlhEenmwFS7TjV JSj8VWp1/vVwl0OkoaO2gRSYGxPP0ojRNPo7HEfbT3psARgLBOtqS509Pi44nuJP6lRvLf 3w2FpUyTrs7F8ANoNczAOSHuMdy/Bt+rfBfWa6Jpqv+/n87JGnvfRwBaewZxoyOl7RP4is WPeJi+13YO7K6tYgOAao8N6766fP2KYxj/VfQp5lWvN3hj9hVOyX72E7Wqjnoquy2B7cJu FUrWhxcS4fHDgYrTran1/Q9etQUgavYLi8sV5xmMFcrlsWHY+smJTGdZI5KKAQ== Date: Mon, 6 May 2024 09:17:48 +0200 From: Miquel Raynal To: Keguang Zhang via B4 Relay Cc: keguang.zhang@gmail.com, Richard Weinberger , Vignesh Raghavendra , Rob Herring , Krzysztof Kozlowski , Conor Dooley , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH v7 2/3] mtd: rawnand: Enable monolithic read when reading subpages Message-ID: <20240506091748.18c120d5@xps-13> In-Reply-To: <20240430-loongson1-nand-v7-2-60787c314fa4@gmail.com> References: <20240430-loongson1-nand-v7-0-60787c314fa4@gmail.com> <20240430-loongson1-nand-v7-2-60787c314fa4@gmail.com> Organization: Bootlin X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-GND-Sasl: miquel.raynal@bootlin.com Hi, devnull+keguang.zhang.gmail.com@kernel.org wrote on Tue, 30 Apr 2024 19:11:11 +0800: > From: Keguang Zhang >=20 > nand_read_subpage() reads data and ECC data by two separate > operations. > This patch allows the NAND controllers who support > monolithic page read to do subpage read by a single operation, > which is more effective than nand_read_subpage(). I am a bit puzzled by this change. Usually nand_read_subpage is used for optimizations (when less data than a full page must be retrieved). I know it may be used in other cases (because it's easier for the core in order to support a wide range of controllers). Can you please show a speed test showing the results before I consider merging this patch? The monolithic thing was not supposed to improve throughput but to help with very limited controllers. Thanks, Miqu=C3=A8l