From patchwork Wed Dec 5 09:46:23 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sasha Levin X-Patchwork-Id: 10713679 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9547E1057 for ; Wed, 5 Dec 2018 10:01:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 850642CD44 for ; Wed, 5 Dec 2018 10:01:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 79AC22CD3B; Wed, 5 Dec 2018 10:01:52 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 35BF92CD45 for ; Wed, 5 Dec 2018 10:01:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727866AbeLEJsz (ORCPT ); Wed, 5 Dec 2018 04:48:55 -0500 Received: from mail.kernel.org ([198.145.29.99]:54938 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727337AbeLEJsy (ORCPT ); Wed, 5 Dec 2018 04:48:54 -0500 Received: from sasha-vm.mshome.net (unknown [213.57.143.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B4AB32087F; Wed, 5 Dec 2018 09:48:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544003333; bh=vZPSzNYPMiOhOKC4E6xYUZ0lqyp+YSxDWyBqB4W23Yg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GGTW8VOYAtDSfExYklj3+NbuzrKL1kC7qKRheCisJQvvh5ysPGV5elIE7s6SnK6ns QAxngEbXw82KeCzZYTcS5knJPHEr1a6I5CP5OsxLcRIQvT+PjlBV7jluZtnBnIOqrq NqCjIM76pUEn7v/GxFv2c1U5pknm6XGVrgLhh86c= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Martin Kelly , Stable@vger.kernel.org, Jonathan Cameron , Sasha Levin , linux-iio@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 02/45] iio:st_magn: Fix enable device after trigger Date: Wed, 5 Dec 2018 04:46:23 -0500 Message-Id: <20181205094706.7225-2-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181205094706.7225-1-sashal@kernel.org> References: <20181205094706.7225-1-sashal@kernel.org> Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Martin Kelly [ Upstream commit fe5192ac81ad0d4dfe1395d11f393f0513c15f7f ] Currently, we enable the device before we enable the device trigger. At high frequencies, this can cause interrupts that don't yet have a poll function associated with them and are thus treated as spurious. At high frequencies with level interrupts, this can even cause an interrupt storm of repeated spurious interrupts (~100,000 on my Beagleboard with the LSM9DS1 magnetometer). If these repeat too much, the interrupt will get disabled and the device will stop functioning. To prevent these problems, enable the device prior to enabling the device trigger, and disable the divec prior to disabling the trigger. This means there's no window of time during which the device creates interrupts but we have no trigger to answer them. Fixes: 90efe055629 ("iio: st_sensors: harden interrupt handling") Signed-off-by: Martin Kelly Tested-by: Denis Ciocca Cc: Signed-off-by: Jonathan Cameron Signed-off-by: Sasha Levin --- drivers/iio/magnetometer/st_magn_buffer.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/drivers/iio/magnetometer/st_magn_buffer.c b/drivers/iio/magnetometer/st_magn_buffer.c index 0a9e8fadfa9d..37ab30566464 100644 --- a/drivers/iio/magnetometer/st_magn_buffer.c +++ b/drivers/iio/magnetometer/st_magn_buffer.c @@ -30,11 +30,6 @@ int st_magn_trig_set_state(struct iio_trigger *trig, bool state) return st_sensors_set_dataready_irq(indio_dev, state); } -static int st_magn_buffer_preenable(struct iio_dev *indio_dev) -{ - return st_sensors_set_enable(indio_dev, true); -} - static int st_magn_buffer_postenable(struct iio_dev *indio_dev) { int err; @@ -50,7 +45,7 @@ static int st_magn_buffer_postenable(struct iio_dev *indio_dev) if (err < 0) goto st_magn_buffer_postenable_error; - return err; + return st_sensors_set_enable(indio_dev, true); st_magn_buffer_postenable_error: kfree(mdata->buffer_data); @@ -63,11 +58,11 @@ static int st_magn_buffer_predisable(struct iio_dev *indio_dev) int err; struct st_sensor_data *mdata = iio_priv(indio_dev); - err = iio_triggered_buffer_predisable(indio_dev); + err = st_sensors_set_enable(indio_dev, false); if (err < 0) goto st_magn_buffer_predisable_error; - err = st_sensors_set_enable(indio_dev, false); + err = iio_triggered_buffer_predisable(indio_dev); st_magn_buffer_predisable_error: kfree(mdata->buffer_data); @@ -75,7 +70,6 @@ static int st_magn_buffer_predisable(struct iio_dev *indio_dev) } static const struct iio_buffer_setup_ops st_magn_buffer_setup_ops = { - .preenable = &st_magn_buffer_preenable, .postenable = &st_magn_buffer_postenable, .predisable = &st_magn_buffer_predisable, };