From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay7-d.mail.gandi.net (relay7-d.mail.gandi.net [217.70.183.200]) (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 5B25620E6E3 for ; Mon, 2 Jun 2025 14:19:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.200 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748873987; cv=none; b=m4I0AJGbaP6WJOsMSsY5VawpbVZ040iBeCBkJBwNHXP2VGEagNu9c7BXyUBy5yFHRSHAI0/BAWGi3FwAaSRFBNThsnQ/siA6Z/sgOxszI0owxqbG1zk+uLfz/ThcP/NEGfv6KIhYNOhxj0fnr6qfGxC6+IKER6K0wqYo1ANR1Xo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748873987; c=relaxed/simple; bh=Ev6iNL22PFHIL/H7k7mv5eeLl0WdLTXXN8qyBlvf9KQ=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=hs0uB05DJ0wZJqRkaLEM6+1xDigNuAaBWalCM75k9dSBqlXprWfCobbgFbycOo6XbmXoQ7mvsU0ALTwsrzT6K2pDL8cbFor9et2NaKUKSjGe7/6TkBU5vGqh+oSestGJONtBSGFtmgwE3uRd/+23J0gzdGQXTeiin8wGs2lp+zI= 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=Yhcjc4Dx; arc=none smtp.client-ip=217.70.183.200 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="Yhcjc4Dx" Received: by mail.gandi.net (Postfix) with ESMTPSA id 98B1143917; Mon, 2 Jun 2025 14:19:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1748873977; 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=Ev6iNL22PFHIL/H7k7mv5eeLl0WdLTXXN8qyBlvf9KQ=; b=Yhcjc4DxVpktZG2sfeGOKAu/dtCMwVl5FNgFFfgFjN3slTiJUtJJF+ikpi/fX3QH+OYtKA 9KL9rvadfV5+7ugK0PxfdB8Zj8yPYzfxIQ3WbjmPn8JeJCRXuvq0c5Ret7yYt95QYsuny3 0uemBmiFPhwloDZrclMZfGRm5HEvxyzHIiFB2rp4ltO2HWaSMYUuPvPLdh6FXpDq3EQf/u UCT/Ywvwgng4Z8SP13e8Qf98i9yx7h8bvtyu9NOV3ZGqviB/DVS4Ez7+7SeuOf1LqJmpaE sHxb7/R1CrfVnwTbNR7+YL/TftLazYh+CdIOLXUQ3sEcjmSiK02soKfLrKvkfQ== From: Miquel Raynal To: David Regan Cc: linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, bcm-kernel-feedback-list@broadcom.com, william.zhang@broadcom.com, anand.gore@broadcom.com, florian.fainelli@broadcom.com, kamal.dasu@broadcom.com, dan.beygelman@broadcom.com, =?utf-8?Q?=C3=81l?= =?utf-8?Q?varo_Fern=C3=A1ndez?= Rojas , rafal@milecki.pl, computersforpeace@gmail.com, frieder.schrempf@kontron.de, vigneshr@ti.com, richard@nod.at, bbrezillon@kernel.org, kdasu.kdev@gmail.com, jaimeliao.tw@gmail.com, kilobyte@angband.pl, jonas.gorski@gmail.com, dgcbueu@gmail.com, dregan@mail.com Subject: Re: [PATCH] mtd: nand: brcmnand: fix mtd corrected bits stat In-Reply-To: <20250530034713.4165309-1-dregan@broadcom.com> (David Regan's message of "Thu, 29 May 2025 20:46:59 -0700") References: <20250530034713.4165309-1-dregan@broadcom.com> User-Agent: mu4e 1.12.7; emacs 29.4 Date: Mon, 02 Jun 2025 16:19:35 +0200 Message-ID: <87ecw2ns3s.fsf@bootlin.com> 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-State: clean X-GND-Score: -100 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeeffedrtddtgdefjeeltdculddtuddrgeefvddrtddtmdcutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfitefpfffkpdcuggftfghnshhusghstghrihgsvgenuceurghilhhouhhtmecufedtudenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhephffvvefujghffgffkfggtgfgsehtqhertddtreejnecuhfhrohhmpefoihhquhgvlhcutfgrhihnrghluceomhhiqhhuvghlrdhrrgihnhgrlhessghoohhtlhhinhdrtghomheqnecuggftrfgrthhtvghrnhepffeghfejtdefieeguddukedujeektdeihfelleeuieeuveehkedvleduheeivdefnecukfhppedvuddvrddutdehrdduhedtrddvhedvnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehinhgvthepvdduvddruddthedrudehtddrvdehvddphhgvlhhopehlohgtrghlhhhoshhtpdhmrghilhhfrhhomhepmhhiqhhuvghlrdhrrgihnhgrlhessghoohhtlhhinhdrtghomhdpnhgspghrtghpthhtohepvddvpdhrtghpthhtohepughrvghgrghnsegsrhhorggutghomhdrtghomhdprhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehlihhnuhigqdhmthgusehlihhsthhsrdhinhhfrhgruggvrggurdhorhhgpdhrtghpthhtohepsggtmhdqkhgvrhhnvghlqdhfvggvuggsrggtkhdqlhhishhtsegsr hhorggutghomhdrtghomhdprhgtphhtthhopeifihhllhhirghmrdiihhgrnhhgsegsrhhorggutghomhdrtghomhdprhgtphhtthhopegrnhgrnhgurdhgohhrvgessghrohgruggtohhmrdgtohhmpdhrtghpthhtohepfhhlohhrihgrnhdrfhgrihhnvghllhhisegsrhhorggutghomhdrtghomhdprhgtphhtthhopehkrghmrghlrdgurghsuhessghrohgruggtohhmrdgtohhm X-GND-Sasl: miquel.raynal@bootlin.com On 29/05/2025 at 20:46:59 -07, David Regan wrote: > Currently we attempt to get the amount of flipped bits from a hardware > location which is reset on every subpage. Instead obtain total flipped > bits stat from hardware accumulator. In addition identify the correct > maximum subpage corrected bits. This change does not feel correct. We gather two statistics: - the maximum number of bitflips corrected in a single ECC chunk - the total number of bitflips among the whole page The most important one is the former, because it may trigger wear levelling from the top layer (UBI, usually). It feels like you are breaking this, am I wrong? Would you mind to be more explicit otherwise? Thanks, Miqu=C3=A8l