Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752558AbcCKFWN (ORCPT ); Fri, 11 Mar 2016 00:22:13 -0500 Received: from mail-db5eur01on0054.outbound.protection.outlook.com ([104.47.2.54]:15569 "EHLO EUR01-DB5-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750727AbcCKFWL convert rfc822-to-8bit (ORCPT ); Fri, 11 Mar 2016 00:22:11 -0500 From: Noam Camus To: Vineet Gupta , Lada Trimasova CC: "linux-kernel@vger.kernel.org" , "linux-arch@vger.kernel.org" , Alexey Brodkin , "linux-snps-arc@lists.infradead.org" Subject: Re: [PATCH] arc: use little endian accesses Thread-Topic: [PATCH] arc: use little endian accesses Thread-Index: AQHReigvwfe2mS0fOU2Ja6Uq9+fF5Z9TCSkAgACnNdY= Date: Fri, 11 Mar 2016 05:07:09 +0000 Message-ID: References: <1457544064-16167-1-git-send-email-ltrimas@synopsys.com> <1457595846.2868.10.camel@synopsys.com> ,<1457636268.457.34.camel@synopsys.com> In-Reply-To: <1457636268.457.34.camel@synopsys.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: vger.kernel.org; dkim=none (message not signed) header.d=none;vger.kernel.org; dmarc=none action=none header.from=mellanox.com; x-originating-ip: [85.64.158.114] x-ms-office365-filtering-correlation-id: de8e743a-7a85-40a9-6d17-08d3496b0017 x-microsoft-exchange-diagnostics: 1;HE1PR05MB1626;5:5l6k+d+cs/FZvP3x7LGSUN83Kfnzrd5VnuYj80uUt7FOutSU7exz7twZmHRizgjWYgyUgXccaNPFsmyIZvZ/FQ+qRzcg+z7+O4OVBnfbROoDmfNgQWOR7PyZoakF7butG3mXmpDadq+VxZDUjaXGSg==;24:aMqNfIz7XqMI0mOD2YRW51/WGTuW2Ml792WiiUUIs946q/YHAt4EcX6+wZaaWwCNzZuUP4HCzpcnYG+4itEmxaTLNjlCEXxGA4OFIkGUg5g= x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:HE1PR05MB1626; x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:; x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(601004)(2401047)(8121501046)(5005006)(3002001)(10201501046);SRVR:HE1PR05MB1626;BCL:0;PCL:0;RULEID:;SRVR:HE1PR05MB1626; x-forefront-prvs: 087894CD3C x-forefront-antispam-report: SFV:NSPM;SFS:(10009020)(6009001)(377454003)(92566002)(5004730100002)(2906002)(76176999)(50986999)(5001770100001)(189998001)(54356999)(33656002)(4326007)(5003600100002)(74316001)(66066001)(5002640100001)(11100500001)(1220700001)(3846002)(102836003)(87936001)(586003)(10400500002)(122556002)(19580405001)(19580395003)(77096005)(6116002)(86362001)(1096002)(106116001)(93886004)(81166005)(76576001)(3660700001)(5008740100001)(3280700002)(2950100001)(2900100001);DIR:OUT;SFP:1101;SCL:1;SRVR:HE1PR05MB1626;H:HE1PR05MB1625.eurprd05.prod.outlook.com;FPR:;SPF:None;MLV:sfv;LANG:en; spamdiagnosticoutput: 1:23 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT MIME-Version: 1.0 X-OriginatorOrg: Mellanox.com X-MS-Exchange-CrossTenant-originalarrivaltime: 11 Mar 2016 05:07:09.9047 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: a652971c-7d2e-4d9b-a6a4-d149256f461b X-MS-Exchange-Transport-CrossTenantHeadersStamped: HE1PR05MB1626 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 562 Lines: 16 > From: Lada Trimasova > Sent: Thursday, March 10, 2016 8:57 PM > And for example, let's see what happens when we use "readl" in function "serial8250_early_in" in driver/tty/serial/8250. Is your DTS entry includes for serial node following entries: reg-io-width = <4> native-endian; if answer is yes you should expect (in case of big endian compilation) that: port->iotype would be equal to UPIO_MEM32BE, hence no readl() use for this case. This is how it works for me here, it sounds like your case is similar. Regards, Noam