From mboxrd@z Thu Jan 1 00:00:00 1970 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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 917C5C48BD5 for ; Tue, 25 Jun 2019 20:27:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6925D208CB for ; Tue, 25 Jun 2019 20:27:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561494425; bh=4DjDMXCFMiEPojnFZTh8l0f8w6EVPLy4ezbvE1XggGw=; h=In-Reply-To:References:To:From:Subject:Cc:Date:List-ID:From; b=Jc40CCoTgXuuHmx0ku2p/xdOkHjbyEdu+swOYDCeasjCTG+2X3fBbcW9vQNBxjSc8 oeipYr95SNbFUd86HeGrnsCdkS60djLCGPgEd4K5poSPbWw6l66sBJWSXK3v+rgcc2 GGldBETirQU1GR7bomhVIo14vRnDH2HY2IAJ2wso= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727676AbfFYU1E (ORCPT ); Tue, 25 Jun 2019 16:27:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:51104 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726455AbfFYU1D (ORCPT ); Tue, 25 Jun 2019 16:27:03 -0400 Received: from kernel.org (unknown [104.132.0.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B9A9B208CB; Tue, 25 Jun 2019 20:27:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561494422; bh=4DjDMXCFMiEPojnFZTh8l0f8w6EVPLy4ezbvE1XggGw=; h=In-Reply-To:References:To:From:Subject:Cc:Date:From; b=HGnMUm36tBd89ZCYMpakSYGFEW5Ra8p8ujQXGTZBj7wplR2/DDy55cLSCmDONvdHY zvRbTWOTcuq+e3106aW7m2laV8C4uUGsBk5uzvJeZKwhWPPPmBSq+savdLyIs9SkPO 50vQuTR/sLQeXqmcCO0A4QBjA4XFwhvT87/QcdKc= Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable In-Reply-To: <20190620150013.13462-6-narmstrong@baylibre.com> References: <20190620150013.13462-1-narmstrong@baylibre.com> <20190620150013.13462-6-narmstrong@baylibre.com> To: Neil Armstrong , jbrunet@baylibre.com, khilman@baylibre.com From: Stephen Boyd Subject: Re: [RFC/RFT 05/14] soc: amlogic: meson-clk-measure: protect measure with a mutex Cc: linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, martin.blumenstingl@googlemail.com, Neil Armstrong User-Agent: alot/0.8.1 Date: Tue, 25 Jun 2019 13:27:01 -0700 Message-Id: <20190625202702.B9A9B208CB@mail.kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Quoting Neil Armstrong (2019-06-20 08:00:04) > In order to protect clock measuring when multiple process asks for > a mesure, protect the main measure function with mutexes. >=20 > Signed-off-by: Neil Armstrong > --- > drivers/soc/amlogic/meson-clk-measure.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) >=20 > diff --git a/drivers/soc/amlogic/meson-clk-measure.c b/drivers/soc/amlogi= c/meson-clk-measure.c > index 19d4cbc93a17..c470e24f1dfa 100644 > --- a/drivers/soc/amlogic/meson-clk-measure.c > +++ b/drivers/soc/amlogic/meson-clk-measure.c > @@ -11,6 +11,8 @@ > #include > #include > =20 > +static DEFINE_MUTEX(measure_lock); > + > #define MSR_CLK_DUTY 0x0 > #define MSR_CLK_REG0 0x4 > #define MSR_CLK_REG1 0x8 > @@ -360,6 +362,10 @@ static int meson_measure_id(struct meson_msr_id *clk= _msr_id, > unsigned int val; > int ret; > =20 > + ret =3D mutex_lock_interruptible(&measure_lock); Why interruptible? > + if (ret) > + return ret; > + > regmap_write(priv->regmap, MSR_CLK_REG0, 0); > =20 > /* Set measurement duration */