From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pali =?utf-8?q?Roh=C3=A1r?= Subject: Re: runtime check for omap-aes bus access permission (was: Re: 3.13-rc3 (commit 7ce93f3) breaks Nokia N900 DT boot) Date: Sat, 31 Jan 2015 20:06:18 +0100 Message-ID: <201501312006.18465@pali> References: <20131206213613.GA19648@earth.universe> <201501311234.41001@pali> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart1449976.DsASfTbacX"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-we0-f180.google.com ([74.125.82.180]:47017 "EHLO mail-we0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753274AbbAaTGV (ORCPT ); Sat, 31 Jan 2015 14:06:21 -0500 Received: by mail-we0-f180.google.com with SMTP id m14so32460845wev.11 for ; Sat, 31 Jan 2015 11:06:20 -0800 (PST) In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Matthijs van Duin Cc: Tony Lindgren , Sebastian Reichel , linux-omap@vger.kernel.org, Aaro Koskinen , Pavel Machek , Nishanth Menon --nextPart1449976.DsASfTbacX Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable On Saturday 31 January 2015 16:13:39 Matthijs van Duin wrote: > On 31 January 2015 at 12:34, Pali Roh=C3=A1r =20 wrote: > > [ 172.923553] Unhandled fault: external abort on > > non-linefetch (0x1018) at 0xb6f87028 [ 172.930664] In-band > > Error seen by MPU at address 0 >=20 > Also, why is this error so uninformative? A synchronous abort > should at least mention the _physical_ address, type of > access, etc. >=20 > Anyhow, since checking the firewalls/APs to see if you have > permission will probably only get you yet another fault if > things are walled off, the robust way of dealing with this > sort of situation is by probing the device with a read while > trapping bus faults. This also handles modules that are > unreachable for other reasons, e.g. being disabled by eFuse. Just to note that above error output is from device where is=20 signed X-Loader which *enable* omap aes support. So it looks like it is not possible to dump registers which=20 should tell you if kernel has permission or not (in L3 firewall). =2D-=20 Pali Roh=C3=A1r pali.rohar@gmail.com --nextPart1449976.DsASfTbacX Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iEYEABECAAYFAlTNJ6oACgkQi/DJPQPkQ1J9UwCfY9l6RU20h3mqnQ3Pwd4Ne0St VbUAn3Ihm6BXvlbNqX6voQNsLXtybSLH =FAsq -----END PGP SIGNATURE----- --nextPart1449976.DsASfTbacX--