From patchwork Fri Feb 10 10:27:59 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 726485 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3vKWcV048wz9s7D for ; Fri, 10 Feb 2017 21:38:02 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751903AbdBJKiA (ORCPT ); Fri, 10 Feb 2017 05:38:00 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57860 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751966AbdBJKhy (ORCPT ); Fri, 10 Feb 2017 05:37:54 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id ADBF6201FB; Fri, 10 Feb 2017 10:28:36 +0000 (UTC) Received: from shalem.localdomain.com (ovpn-117-212.ams2.redhat.com [10.36.117.212]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v1AAS4jH005761; Fri, 10 Feb 2017 05:28:33 -0500 From: Hans de Goede To: Daniel Vetter , Jani Nikula , =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= , Jarkko Nikula , Wolfram Sang , Len Brown , Andy Shevchenko , Thomas Gleixner , "H . Peter Anvin" Cc: Hans de Goede , intel-gfx , dri-devel@lists.freedesktop.org, Mika Westerberg , Takashi Iwai , "russianneuromancer @ ya . ru" , linux-i2c@vger.kernel.org Subject: [PATCH v3 09/12] i2c: designware-baytrail: Acquire P-Unit access on bus acquire Date: Fri, 10 Feb 2017 11:27:59 +0100 Message-Id: <20170210102802.20898-10-hdegoede@redhat.com> In-Reply-To: <20170210102802.20898-1-hdegoede@redhat.com> References: <20170210102802.20898-1-hdegoede@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Fri, 10 Feb 2017 10:28:36 +0000 (UTC) Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Acquire P-Unit access to stop others from accessing the P-Unit while the PMIC i2c bus is in use. This is necessary because accessing the P-Unit from the kernel may result in the P-Unit trying to access the PMIC i2c bus, which results in a hang when it happens while we own the PMIC i2c bus semaphore. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=155241 Signed-off-by: Hans de Goede Tested-by: tagorereddy Acked-by: Wolfram Sang Acked-by: Jarkko Nikula --- Changes in v2: -Spelling: P-Unit, PMIC -Adjust for iosf_mbi_punit_lock/_unlock to _acquire/_release rename --- drivers/i2c/busses/i2c-designware-baytrail.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c index 3effc9a..7eddc3b 100644 --- a/drivers/i2c/busses/i2c-designware-baytrail.c +++ b/drivers/i2c/busses/i2c-designware-baytrail.c @@ -62,6 +62,8 @@ static void reset_semaphore(struct dw_i2c_dev *dev) dev_err(dev->dev, "iosf failed to reset punit semaphore during write\n"); pm_qos_update_request(&dev->pm_qos, PM_QOS_DEFAULT_VALUE); + + iosf_mbi_punit_release(); } static int baytrail_i2c_acquire(struct dw_i2c_dev *dev) @@ -79,6 +81,8 @@ static int baytrail_i2c_acquire(struct dw_i2c_dev *dev) if (!dev->release_lock) return 0; + iosf_mbi_punit_acquire(); + /* * Disallow the CPU to enter C6 or C7 state, entering these states * requires the punit to talk to the pmic and if this happens while