From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21CAFC43381 for ; Wed, 27 Feb 2019 10:27:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EB2FB20449 for ; Wed, 27 Feb 2019 10:27:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726389AbfB0K1i (ORCPT ); Wed, 27 Feb 2019 05:27:38 -0500 Received: from mga03.intel.com ([134.134.136.65]:16577 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726063AbfB0K1i (ORCPT ); Wed, 27 Feb 2019 05:27:38 -0500 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Feb 2019 02:27:37 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,419,1544515200"; d="scan'208";a="118147955" Received: from lahna.fi.intel.com (HELO lahna) ([10.237.72.157]) by orsmga007.jf.intel.com with SMTP; 27 Feb 2019 02:27:33 -0800 Received: by lahna (sSMTP sendmail emulation); Wed, 27 Feb 2019 12:27:32 +0200 Date: Wed, 27 Feb 2019 12:27:32 +0200 From: Mika Westerberg To: "Sverdlin, Alexander (Nokia - DE/Ulm)" Cc: "linux-mtd@lists.infradead.org" , Marek Vasut , Tudor Ambarus , David Woodhouse , Brian Norris , Boris Brezillon , Richard Weinberger , Bin Meng , "Porte, Romain (Nokia - FR/Paris-Saclay)" , "Fabreges, Pascal (Nokia - FR/Paris-Saclay)" , "stable@vger.kernel.org" Subject: Re: [PATCH v2] spi-nor: intel-spi: Avoid crossing 4K address boundary on read/write Message-ID: <20190227102732.GU2696@lahna.fi.intel.com> References: <20190226112334.401-1-alexander.sverdlin@nokia.com> <20190227095617.20968-1-alexander.sverdlin@nokia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190227095617.20968-1-alexander.sverdlin@nokia.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Wed, Feb 27, 2019 at 09:57:15AM +0000, Sverdlin, Alexander (Nokia - DE/Ulm) wrote: > It was observed that reads crossing 4K address boundary are failing. > > This limitation is mentioned in Intel documents: > > Intel(R) 9 Series Chipset Family Platform Controller Hub (PCH) Datasheet: > > "5.26.3 Flash Access > Program Register Access: > * Program Register Accesses are not allowed to cross a 4 KB boundary..." > > Enhanced Serial Peripheral Interface (eSPI) > Interface Base Specification (for Client and Server Platforms): > > "5.1.4 Address > For other memory transactions, the address may start or end at any byte > boundary. However, the address and payload length combination must not > cross the naturally aligned address boundary of the corresponding Maximum > Payload Size. It must not cross a 4 KB address boundary." > > Avoid this by splitting an operation crossing the boundary into two > operations. > > Cc: stable@vger.kernel.org > Reported-by: Romain Porte > Tested-by: Pascal Fabreges > Signed-off-by: Alexander Sverdlin > --- > Changelog: > v2: More macros! As Mika suggested. > > drivers/mtd/spi-nor/intel-spi.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/mtd/spi-nor/intel-spi.c b/drivers/mtd/spi-nor/intel-spi.c > index af0a220..8c279c4 100644 > --- a/drivers/mtd/spi-nor/intel-spi.c > +++ b/drivers/mtd/spi-nor/intel-spi.c > @@ -632,6 +632,10 @@ static ssize_t intel_spi_read(struct spi_nor *nor, loff_t from, size_t len, > while (len > 0) { > block_size = min_t(size_t, len, INTEL_SPI_FIFO_SZ); > > + /* Read cannot cross 4K boundary */ > + blocksize = min(from + block_size, round_up(from + 1, SZ_4K)) - > + from; Nit: It looks better if you put it into one line like: blocksize = min(from + block_size, round_up(from + 1, SZ_4K)) - from; Regardless of that, Acked-by: Mika Westerberg