From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754659AbdDKLi5 (ORCPT ); Tue, 11 Apr 2017 07:38:57 -0400 Received: from mail.free-electrons.com ([62.4.15.54]:56184 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752291AbdDKLi4 (ORCPT ); Tue, 11 Apr 2017 07:38:56 -0400 Date: Tue, 11 Apr 2017 13:38:54 +0200 From: Boris Brezillon To: Sekhar Nori Cc: Richard Weinberger , David Woodhouse , Brian Norris , Marek Vasut , Cyrille Pitchen , , Subject: Re: [PATCH] mtd: nand: davinci: add comment on NAND subpage write status on keystone Message-ID: <20170411133854.0d3e870c@bbrezillon> In-Reply-To: <079de6bbc3285ab09e4ac25e78b947286080cee5.1490884624.git.nsekhar@ti.com> References: <079de6bbc3285ab09e4ac25e78b947286080cee5.1490884624.git.nsekhar@ti.com> X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 30 Mar 2017 20:09:30 +0530 Sekhar Nori wrote: > Add a comment clarifying that NAND subpage write on keystone works, > but is not being enabled in the interest of backward compatibility. Applied. Thanks, Boris > > Signed-off-by: Sekhar Nori > --- > drivers/mtd/nand/davinci_nand.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/mtd/nand/davinci_nand.c b/drivers/mtd/nand/davinci_nand.c > index 27fa8b87cd5f..531c51991e57 100644 > --- a/drivers/mtd/nand/davinci_nand.c > +++ b/drivers/mtd/nand/davinci_nand.c > @@ -581,6 +581,17 @@ static struct davinci_nand_pdata > "ti,davinci-nand-use-bbt")) > pdata->bbt_options = NAND_BBT_USE_FLASH; > > + /* > + * Since kernel v4.8, this driver has been fixed to enable > + * use of 4-bit hardware ECC with subpages and verified on > + * TI's keystone EVMs (K2L, K2HK and K2E). > + * However, in the interest of not breaking systems using > + * existing UBI partitions, sub-page writes are not being > + * (re)enabled. If you want to use subpage writes on Keystone > + * platforms (i.e. do not have any existing UBI partitions), > + * then use "ti,davinci-nand" as the compatible in your > + * device-tree file. > + */ > if (of_device_is_compatible(pdev->dev.of_node, > "ti,keystone-nand")) { > pdata->options |= NAND_NO_SUBPAGE_WRITE;