From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from a.ns.miles-group.at ([95.130.255.143] helo=radon.swed.at)
 by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux))
 id 1atdKJ-0003Hb-6Y
 for linux-mtd@lists.infradead.org; Fri, 22 Apr 2016 15:49:04 +0000
Subject: Re: Pass -EUCLEN to userspace?
To: Boris Brezillon <boris.brezillon@free-electrons.com>,
 Sascha Hauer <s.hauer@pengutronix.de>
References: <20160420132516.GC31101@pengutronix.de>
 <20160422172456.7aaf301c@bbrezillon> <20160422172802.4fa830d1@bbrezillon>
Cc: linux-mtd@lists.infradead.org, kernel@pengutronix.de,
 Daniel Walter <dwalter@sigma-star.at>
From: Richard Weinberger <richard@nod.at>
Message-ID: <571A47D3.6040602@nod.at>
Date: Fri, 22 Apr 2016 17:48:35 +0200
MIME-Version: 1.0
In-Reply-To: <20160422172802.4fa830d1@bbrezillon>
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 8bit
List-Id: Linux MTD discussion mailing list <linux-mtd.lists.infradead.org>
List-Unsubscribe: <http://lists.infradead.org/mailman/options/linux-mtd>,
 <mailto:linux-mtd-request@lists.infradead.org?subject=unsubscribe>
List-Archive: <http://lists.infradead.org/pipermail/linux-mtd/>
List-Post: <mailto:linux-mtd@lists.infradead.org>
List-Help: <mailto:linux-mtd-request@lists.infradead.org?subject=help>
List-Subscribe: <http://lists.infradead.org/mailman/listinfo/linux-mtd>,
 <mailto:linux-mtd-request@lists.infradead.org?subject=subscribe>

Sascha, Boris,

Am 22.04.2016 um 17:28 schrieb Boris Brezillon:
>>> I am currently working on a program similar to ubihealthd, just for raw
>>> mtd pages, not UBI. Basically I want to find out in userspace if my Nand needs
>>> scrubbing. Is it possible somehow to get this information in userspace?
>>
>> Actually we discussed that a year ago with Richard. I told him that we
>> should put the read/write/erase statistics at the MTD level so that
>> other MTD users (including userspace programs) could use the same infra
>> for non-UBI partitions (I need that for the UBOOT and SPL partitions).
>>
>> My suggestion was to store those information at the MTD level, and let
>> UBI implement its own scrubbing layer on top of that, but Richard
>> decided to go for a simpler approach for its first implementation.

Yeah, I did a first implementation on UBI layer as it had everything we need
and I didn't want to replicate UBI at MTD level.
Another reason is that we were not sure how sophisticated ubihealthd needs to be.

Sasha, what exactly is your use case and why is the UBI approach not sufficient for you?
On Linux MTD access should only happen through UBI and UBOOT/SPL partitions stay untouched.

Thanks,
//richard