From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754666AbdC3Okf (ORCPT ); Thu, 30 Mar 2017 10:40:35 -0400 Received: from fllnx210.ext.ti.com ([198.47.19.17]:19704 "EHLO fllnx210.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754256AbdC3Oke (ORCPT ); Thu, 30 Mar 2017 10:40:34 -0400 From: Sekhar Nori To: Boris Brezillon CC: Richard Weinberger , David Woodhouse , Brian Norris , Marek Vasut , Cyrille Pitchen , , , Sekhar Nori Subject: [PATCH] mtd: nand: davinci: add comment on NAND subpage write status on keystone Date: Thu, 30 Mar 2017 20:09:30 +0530 Message-ID: <079de6bbc3285ab09e4ac25e78b947286080cee5.1490884624.git.nsekhar@ti.com> X-Mailer: git-send-email 2.9.0 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a comment clarifying that NAND subpage write on keystone works, but is not being enabled in the interest of backward compatibility. 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; -- 2.9.0