From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751159AbeCINzz (ORCPT ); Fri, 9 Mar 2018 08:55:55 -0500 Received: from mail.kernel.org ([198.145.29.99]:37982 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751056AbeCINzy (ORCPT ); Fri, 9 Mar 2018 08:55:54 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D384120685 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=jhogan@kernel.org Date: Fri, 9 Mar 2018 13:55:49 +0000 From: James Hogan To: Matt Redfearn Cc: Ralf Baechle , linux-mips@linux-mips.org, Paul Burton , Dengcheng Zhu , linux-kernel@vger.kernel.org, Ingo Molnar , Mark Rutland Subject: Re: [PATCH v3] MIPS: pm-cps: Block system suspend when a JTAG probe is present Message-ID: <20180309135548.GF24558@saruman> References: <1519120696-30658-1-git-send-email-matt.redfearn@mips.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="NQTVMVnDVuULnIzU" Content-Disposition: inline In-Reply-To: <1519120696-30658-1-git-send-email-matt.redfearn@mips.com> User-Agent: Mutt/1.7.2 (2016-11-26) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --NQTVMVnDVuULnIzU Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Feb 20, 2018 at 09:58:16AM +0000, Matt Redfearn wrote: > If a JTAG probe is connected to a MIPS cluster, then the CPC detects it > and latches the CPC.STAT_CONF.EJTAG_PROBE bit to 1. While set, > attempting to send a power-down command to a core will be blocked, and > the CPC will instead send the core to clock-off state. This can > interfere with systems fully entering a low power state where all > cores, CM, GIC, etc are powered down. >=20 > Detect that a JTAG probe is / has been connected to the cluster and > block the suspend attempt. >=20 > Attempting to suspend the system while a JTAG probe is connected now > yields: > # echo mem > /sys/power/state > [ 11.654000] PM: Syncing filesystems ... done. > [ 11.658000] JTAG probe is connected - abort suspend > -sh: echo: write error: Operation not permitted > # >=20 > To restore suspend, the JTAG probe should be disconnected or put into > quiescent state. Platform code can then clear the > CPC.STAT_CONF.EJTAG_PROBE bit. >=20 > Reported-by: Ed Blake > Signed-off-by: Matt Redfearn Thanks, applied for 4.17. Cheers James --NQTVMVnDVuULnIzU Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEd80NauSabkiESfLYbAtpk944dnoFAlqikmQACgkQbAtpk944 dnoj5w//b2/C5942IMlU/7MwmyAJO/OGYb1Tl1zaom2GiEfWU8LtKMtUJWY95B6C f0VWRrpSqB1yDi6Ipg89YtH0XuUG7P1VZ9OmWmwfnHI8NAF28l6Ypd6N2sDbHl/r 8yikABtHHRPgwcpBTGDD9ottgIrcgy6UaNatUTVY8n4cldIDOrDTxUk3Jd9/BRRJ 4b/SsLfewVMQb4oibuX134O5WxyWWLP/wfiLHs54dU61qOl4KvSmq8o42XKR3c2v ZEiXjxHVU6FBP/+uTjXwF2uVXS58RUAm9BZAJhcg3RAPqbkq9v4ycQ6WgOOHw9Re eutnwqjDoAEiLJX1vZ8v1MPyUZo4P59DBL9pSitqKUUpAS/ihNIIob7xXOT9I+4F yYr4P7NcQiSGp8cg/6nsJY8DGh91dSSmclvso0ov32XYfhMfvjV50NdaSjbxyN4o O6pkb05JeLGm3lLtcUAYBlfhql1TiO7lGnmjXNI4IU9+fTHZFA251qa84cXKU88U hO/aJpJVy2qyoOprphNXHBCRfwdA2IrCoI0vCAn2spi+s3BCOS08OUC8o1UaDHcR Q22RYCYaUVsABnvXGnGvs/g6lvFSMaLwH7bIv3t1OGR4hDhH4Tt4E78tFn36zceq KhI2Ka2aXPSJ0jiEgtRV+XQPT6zlWPfYGWkSDlH6x2ck5b/xl5Q= =bC1I -----END PGP SIGNATURE----- --NQTVMVnDVuULnIzU--