Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755817AbbBPQ7j (ORCPT ); Mon, 16 Feb 2015 11:59:39 -0500 Received: from down.free-electrons.com ([37.187.137.238]:58669 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753250AbbBPQ7g (ORCPT ); Mon, 16 Feb 2015 11:59:36 -0500 Message-ID: <54E22168.7070703@free-electrons.com> Date: Mon, 16 Feb 2015 13:57:12 -0300 From: Ezequiel Garcia User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Maxime Ripard , Thomas Petazzoni CC: Gregory Clement , Jason Cooper , Andrew Lunn , Sebastian Hesselbarth , Brian Norris , Lior Amsalem , Tawfik Bayouk , Thomas Petazzoni , Seif Mazareeb , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Sudhakar Gundubogula , Nadav Haklai , Boris Brezillon , linux-mtd@lists.infradead.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v3 1/2] mtd: nand: pxa3xx: Fix PIO FIFO draining References: <1424091072-7738-1-git-send-email-maxime.ripard@free-electrons.com> <1424091072-7738-2-git-send-email-maxime.ripard@free-electrons.com> <20150216172753.5e92739a@free-electrons.com> <20150216164134.GE25269@lukather> In-Reply-To: <20150216164134.GE25269@lukather> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2355 Lines: 64 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On 02/16/2015 01:41 PM, Maxime Ripard wrote: > On Mon, Feb 16, 2015 at 05:27:53PM +0100, Thomas Petazzoni wrote: >> Dear Maxime Ripard, >> >> On Mon, 16 Feb 2015 13:51:11 +0100, Maxime Ripard wrote: >> >>> + while (index < (len * 4)) { >>> + u32 timeout; >>> + >>> + __raw_readsl(info->mmio_base + NDDB, data + index, 8); >> >> Are you guaranteed that 'len' is a multiple of 32 bytes? > > I don't know if you're guaranteed of anything, but the controller > supports only 512, 2k, 4k and 8k pages, which are all mutiples of 32 > bytes. > 'len' here comes from: do_bytes = min(info->data_size, info->chunk_size); and DIV_ROUND_UP(do_bytes, 4) Where chunk_size is the size we want to read/write in each command step (keep in mind that with extended commands we issue multiple commands, and read/write data in chunks for each page). And data_size is initialized at mtd->writesize (i.e. the size of a page). Given all the flash pages I'm aware of are multiples of 32-bytes, and given a chunk is either a quarter or half a page... I'd say it's guaranteed to be 32-byte multiple, but perhaps it's a good idea to enforce it. - -- Ezequiel Garc?a, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJU4iFfAAoJEIOKbhOEIHKiOuMQAK0yiPyjBKRcqX8qrpG9Ljcq JVhJTjn7VdiWhoh0n9BOt5bV3K0wAvcbt3LZvpGwf1EOifBaZB+f2QskZNLDUXyC JXPaonbdUqabEU0n9frduc9xBgbPhrwL4X0RzbJ0xZ+A2FrPt/80qUe8lsDmykH9 dyl3FOL3EQQiQ83D1VefkYbeDjaunvhA7Lfi7CcdPSFRv1FE47NQUW/8OjvZVczx uPcvdNj4818aXtFyOJQbR9xWOhVh7nxPlU8flHZPHuJ5WVCGWBbt++/4vmK+LZkv aZQ8W6dGiKI3ayT+PQ7nsETmoXZcjWTihq+nW+Ie2vs5PZf1iME5RYarLSKsc0Ac 4GjLnd4+0H3jeInvJ0MLw0dhkYM4PLkzp4CPo4vrH8z5F3cLXxaRkZYuv7gChden C2VITr9C8p1OSQJ2mF8m9gWdExkEuuy7q6vURx74C4KaeQA2R4ARAROm85o6JtmN dhozZIFrJQGwGuB5+7MI3yJj4OpFsBkxoq6U1JNDTwYnu3SnMOdwvq9kwqGXgR2I yQlu6MO6DYHkMtmw//kkqX+vnyhGexrFoesOyG4d40mOgyGYqyk+oadV7pNh2g5Y nXGr21Li80N65Sk+RaOFlvmIPaQ45Xn6gS7ckHcVVCZI9HAu87n5n15HEtfaj4Dc r9FkTUgw9cqcio5EVfEs =nkDF -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/