From patchwork Sun Oct 23 19:10:28 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Russell King (Oracle)" X-Patchwork-Id: 9391187 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4A89A60762 for ; Sun, 23 Oct 2016 19:16:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3DDBE28B53 for ; Sun, 23 Oct 2016 19:16:37 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 32C7B28B56; Sun, 23 Oct 2016 19:16:37 +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=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id C821028B53 for ; Sun, 23 Oct 2016 19:16:36 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1byOEY-0005kt-JJ; Sun, 23 Oct 2016 19:15:02 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:3201:214:fdff:fe10:1be6]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1byOCR-0002rE-N7 for linux-arm-kernel@lists.infradead.org; Sun, 23 Oct 2016 19:12:55 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2014; h=Date:Sender:Message-Id:Content-Type:Content-Transfer-Encoding:MIME-Version:Subject:To:From:References:In-Reply-To; bh=/a8vPE9f4PrLNsW+pfsbIPV5Dy3nfmjMRiK2abkf0Y8=; b=CyR+MU4EradXXYJKa8pceLJsI/KkuO1jfmuGUn78bThaRFsBPJLAmlRMHDuDKowPRugjI+AzEgyEs/Vxa6KEGQhctIiT/WBhSDs2bj/LQhDLi7qyDM+R3oQ8wjedHPCSyQyapbE5iVOJug0avx0sdjZKYO+C0u65FNBp4KVjBIk=; Received: from e0022681537dd.dyn.armlinux.org.uk ([2002:4e20:1eda:1:222:68ff:fe15:37dd]:35562 helo=rmk-PC.armlinux.org.uk) by pandora.armlinux.org.uk with esmtpsa (TLSv1:AES128-SHA:128) (Exim 4.82_1-5b7a7c0-XX) (envelope-from ) id 1byOA9-0001ky-R3; Sun, 23 Oct 2016 20:10:29 +0100 Received: from rmk by rmk-PC.armlinux.org.uk with local (Exim 4.82_1-5b7a7c0-XX) (envelope-from ) id 1byOA8-0005yS-TQ; Sun, 23 Oct 2016 20:10:28 +0100 In-Reply-To: <20161023191002.GJ1041@n2100.armlinux.org.uk> References: <20161023191002.GJ1041@n2100.armlinux.org.uk> From: Russell King To: dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH RFC 01/10] drm/i2c: tda998x: avoid race in tda998x_encoder_mode_set() MIME-Version: 1.0 Content-Disposition: inline Message-Id: Date: Sun, 23 Oct 2016 20:10:28 +0100 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20161023_121252_462852_E5BD4978 X-CRM114-Status: GOOD ( 12.16 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP As priv->audio_params can now be changed at run time, we need to be more careful about how we deal with a mode set. We must take the audio lock while checking if there's a valid audio configuration. However, it's slightly worse than that - during mode set, we mute the audio, and it must not be unmuted until we have finished the mode set. It is possible that the audio side may start while a mode set is in progress, so take the audio_mutex lock around the whole mode setting procedure. Signed-off-by: Russell King --- drivers/gpu/drm/i2c/tda998x_drv.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c b/drivers/gpu/drm/i2c/tda998x_drv.c index 9798d400d817..d72bc30a3bce 100644 --- a/drivers/gpu/drm/i2c/tda998x_drv.c +++ b/drivers/gpu/drm/i2c/tda998x_drv.c @@ -1074,13 +1074,12 @@ tda998x_encoder_mode_set(struct drm_encoder *encoder, tda998x_write_avi(priv, adjusted_mode); - if (priv->audio_params.format != AFMT_UNUSED) { - mutex_lock(&priv->audio_mutex); + mutex_lock(&priv->audio_mutex); + if (priv->audio_params.format != AFMT_UNUSED) tda998x_configure_audio(priv, &priv->audio_params, adjusted_mode->clock); - mutex_unlock(&priv->audio_mutex); - } + mutex_unlock(&priv->audio_mutex); } }