From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753270Ab2DYPNr (ORCPT ); Wed, 25 Apr 2012 11:13:47 -0400 Received: from mail-lpp01m010-f46.google.com ([209.85.215.46]:41849 "EHLO mail-lpp01m010-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750757Ab2DYPNp (ORCPT ); Wed, 25 Apr 2012 11:13:45 -0400 Subject: Re: [PATCH v3.4-rc3] MTD: NAND: ams-delta: Fix request_mem_region() failure From: Artem Bityutskiy Reply-To: dedekind1@gmail.com To: Janusz Krzysztofik Cc: David Woodhouse , Tony Lindgren , Artem Bityutskiy , linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, linux-omap@vger.kernel.org Date: Wed, 25 Apr 2012 18:13:38 +0300 In-Reply-To: <1334670557-25640-1-git-send-email-jkrzyszt@tis.icnet.pl> References: <1334670557-25640-1-git-send-email-jkrzyszt@tis.icnet.pl> Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-wruPd1P8yR95skTx5DEE" X-Mailer: Evolution 3.0.3 (3.0.3-1.fc15) Message-ID: <1335366823.6356.11.camel@koala> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-wruPd1P8yR95skTx5DEE Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2012-04-17 at 15:49 +0200, Janusz Krzysztofik wrote: > A call to request_mem_region() has been introduced in the omap-gpio > driver recently (commit 96751fcbe5438e95514b025e9cee7a6d38038f40, > "gpio/omap: Use devm_ API and add request_mem_region"). This change > prevented the Amstrad Delta NAND driver, which was doing the same in > order to take control over OMAP MPU I/O lines that the NAND device hangs > off, from loading successfully. >=20 > There is another driver, omap-keypad, which also manipulates OMAP MPUIO > registers, but has never been calling request_mem_region() on startup, > so it's not affected by the change in the gpio-omap and works correctly. >=20 > Drop request_mem_region() call and related bits from ams-delta NAND > driver. >=20 > Created and tested against linux-3.4-rc3. >=20 > Signed-off-by: Janusz Krzysztofik How about race conditions? Where is the guarantee that these 2 drivers won't affect each other when doing I/O at the same time to the same HW resources? --=20 Best Regards, Artem Bityutskiy --=-wruPd1P8yR95skTx5DEE Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQEcBAABAgAGBQJPmBSiAAoJEJtuLFy+q7felSkIAI6o7Jf26D3n4Z5ar2Fbpz88 lYR7XtaE0wkuCzfwJGqIUodUClIuK9OaLzklXdRXhUGlElW9UO9moF+5jFYsFLcJ vFc5N0YJIityhRe9I9lkagw2es5bEUw0hiGdSruQWCOYtYpTTxg3cjkpvmg66VXK C5my7xT+4bWz21xU76vINVXPJPAonmWl949ISgDVY9MtjpPgU4iFnuHuIXcMRVVk DtzBChj9ZIwYy+SWA2CtYftr/ifRATn/vIZMcqCL7ZiIpm2dkzm/erpvntpQ04C1 MNVUrgbYAzI/Gm1I7h3QAWAogBLBxGe7Th9wJ1LUlYOytqDiCSFvkT8cwvMmstk= =Q+rG -----END PGP SIGNATURE----- --=-wruPd1P8yR95skTx5DEE--