From patchwork Sat May 8 06:02:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leilk Liu X-Patchwork-Id: 432756 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CCC5FC433ED for ; Sat, 8 May 2021 06:02:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A8AB06145E for ; Sat, 8 May 2021 06:02:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229531AbhEHGDg (ORCPT ); Sat, 8 May 2021 02:03:36 -0400 Received: from Mailgw01.mediatek.com ([1.203.163.78]:28806 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S229473AbhEHGDg (ORCPT ); Sat, 8 May 2021 02:03:36 -0400 X-UUID: 943db313235c48f4ab6d6ade246fc35c-20210508 X-UUID: 943db313235c48f4ab6d6ade246fc35c-20210508 Received: from mtkcas32.mediatek.inc [(172.27.4.253)] by mailgw01.mediatek.com (envelope-from ) (mailgw01.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 1994536755; Sat, 08 May 2021 14:02:31 +0800 Received: from mtkcas07.mediatek.inc (172.21.101.84) by MTKMBS31N1.mediatek.inc (172.27.4.69) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Sat, 8 May 2021 14:02:20 +0800 Received: from localhost.localdomain (10.17.3.153) by mtkcas07.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Sat, 8 May 2021 14:02:19 +0800 From: Leilk Liu To: Mark Brown CC: Mark Rutland , Matthias Brugger , , , , , , Leilk Liu Subject: [PATCH] spi: take the SPI IO-mutex in the spi_set_cs_timing method Date: Sat, 8 May 2021 14:02:14 +0800 Message-ID: <20210508060214.1485-1-leilk.liu@mediatek.com> X-Mailer: git-send-email 2.18.0 MIME-Version: 1.0 X-TM-SNTS-SMTP: BC75931E69A775349CBFFC250E38064680A523688CABCE0898A061ACCED4A45F2000:8 X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org this patch takes the io_mutex to prevent an unprotected HW register modification in the set_cs_timing callback. Fixes: 4cea6b8cc34e ("spi: add power control when set_cs_timing") Signed-off-by: Leilk Liu --- drivers/spi/spi.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 2350d131871b..6bda471b9621 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -3459,9 +3459,12 @@ int spi_set_cs_timing(struct spi_device *spi, struct spi_delay *setup, if (spi->controller->set_cs_timing && !(spi->cs_gpiod || gpio_is_valid(spi->cs_gpio))) { + mutex_lock(&spi->controller->io_mutex); + if (spi->controller->auto_runtime_pm) { status = pm_runtime_get_sync(parent); if (status < 0) { + mutex_unlock(&spi->controller->io_mutex); pm_runtime_put_noidle(parent); dev_err(&spi->controller->dev, "Failed to power device: %d\n", status); @@ -3472,11 +3475,13 @@ int spi_set_cs_timing(struct spi_device *spi, struct spi_delay *setup, hold, inactive); pm_runtime_mark_last_busy(parent); pm_runtime_put_autosuspend(parent); - return status; } else { - return spi->controller->set_cs_timing(spi, setup, hold, + status = spi->controller->set_cs_timing(spi, setup, hold, inactive); } + + mutex_unlock(&spi->controller->io_mutex); + return status; } if ((setup && setup->unit == SPI_DELAY_UNIT_SCK) ||