From patchwork Sun Jan 1 20:15:20 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: 710071 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 3tsBKN3fDrz9sQw for ; Mon, 2 Jan 2017 07:15:36 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932432AbdAAUPf (ORCPT ); Sun, 1 Jan 2017 15:15:35 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36136 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932229AbdAAUPf (ORCPT ); Sun, 1 Jan 2017 15:15:35 -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 270083B706; Sun, 1 Jan 2017 20:15:36 +0000 (UTC) Received: from shalem.localdomain.com (vpn1-7-169.ams2.redhat.com [10.36.7.169]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v01KFMJA027103; Sun, 1 Jan 2017 15:15:33 -0500 From: Hans de Goede To: Jarkko Nikula , Wolfram Sang , Len Brown , Andy Shevchenko Cc: Mika Westerberg , Jani Nikula , =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= , Takashi Iwai , "russianneuromancer @ ya . ru" , linux-i2c@vger.kernel.org, intel-gfx , Hans de Goede Subject: [PATCH v5 5/6] i2c: designware-baytrail: Fix race when resetting the semaphore Date: Sun, 1 Jan 2017 21:15:20 +0100 Message-Id: <20170101201521.12364-5-hdegoede@redhat.com> In-Reply-To: <20170101201521.12364-1-hdegoede@redhat.com> References: <20170101201521.12364-1-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 [10.5.110.30]); Sun, 01 Jan 2017 20:15:36 +0000 (UTC) Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Use iosf_mbi_modify instead of iosf_mbi_read + iosf_mbi_write so that we keep the iosf_mbi_lock locked during the read-modify-write done to reset the semaphore. Signed-off-by: Hans de Goede Reviewed-by: Andy Shevchenko Acked-by: Jarkko Nikula --- Changes in v5: -New patch in v5 of this patch-set --- drivers/i2c/busses/i2c-designware-baytrail.c | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c index 650a700..8df529c 100644 --- a/drivers/i2c/busses/i2c-designware-baytrail.c +++ b/drivers/i2c/busses/i2c-designware-baytrail.c @@ -47,15 +47,8 @@ static int get_sem(struct dw_i2c_dev *dev, u32 *sem) static void reset_semaphore(struct dw_i2c_dev *dev) { - u32 data; - - if (iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, PUNIT_SEMAPHORE, &data)) { - dev_err(dev->dev, "iosf failed to reset punit semaphore during read\n"); - return; - } - - data &= ~PUNIT_SEMAPHORE_BIT; - if (iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE, PUNIT_SEMAPHORE, data)) + if (iosf_mbi_modify(BT_MBI_UNIT_PMC, MBI_REG_READ, PUNIT_SEMAPHORE, + 0, PUNIT_SEMAPHORE_BIT)) dev_err(dev->dev, "iosf failed to reset punit semaphore during write\n"); pm_qos_update_request(&dev->pm_qos, PM_QOS_DEFAULT_VALUE);