From mboxrd@z Thu Jan 1 00:00:00 1970 From: boris.brezillon@free-electrons.com (Boris Brezillon) Date: Thu, 1 Oct 2015 17:07:43 +0200 Subject: [PATCH] mtd: nand: pass page number to ecc->write_xxx() methods In-Reply-To: <1440436219-31625-1-git-send-email-boris.brezillon@free-electrons.com> References: <1440436219-31625-1-git-send-email-boris.brezillon@free-electrons.com> Message-ID: <20151001170743.3aa0d6fa@bbrezillon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Brian, On Mon, 24 Aug 2015 19:10:19 +0200 Boris Brezillon wrote: > The ->read_xxx() methods are all passed the page number the NAND controller > is supposed to read, but ->write_xxx() do not have such a parameter. > > This is a problem if we want to properly implement data > scrambling/randomization in order to mitigate MLC sensibility to repeated > pattern: to prevent bitflips in adjacent pages in the same block we need > to avoid repeating the same pattern at the same offset in those pages, > hence the randomizer/scrambler engine need to be passed the page value > in order to adapt its seed accordingly. > > Moreover, adding the page parameter the ->write_xxx() methods add some > consistency to the current model. Apparently nobody complained (or nobody cares :-)) about that patch, and I'll really need the page information if I want to support randomization/scrambling in the sunxi driver. Do you have any objections to this patch (I can rebase it on mainline and check if new drivers have been added since the submission)? I remember you pointed a trick you've used in the brcmnand driver to get this page information (storing it during the ->cmdfunc() or ->ctrl_cmd() call), but it would be way easier to have it directly in the ecc->write_xxx() parameters... Best Regards, Boris -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com