From patchwork Thu Nov 21 07:29:10 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bibby Hsieh X-Patchwork-Id: 11255823 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 366FB14E5 for ; Thu, 21 Nov 2019 07:29:39 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F34B820855 for ; Thu, 21 Nov 2019 07:29:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Z1zrTI0h"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b="dF7WIzR/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F34B820855 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=mediatek.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=MU2GLK9HSHv3UXgerpkFRx3eSjFBk3UQ/Y1K0WO1rvs=; b=Z1zrTI0heeLr3E Z3LopnmC7xrdfUOdfI5CUT7tw+PvRzEG+IxbKeTAMnFq7UPlg0wcU33rwFQtliSo3ieHBGfFq4N51 haFJpv/ncSaee8BbixMeVAAym00RMD8WaG00kRWvv8BDwR16Pnl0Mlo61ukHBQV60/vlrGmOZcOwq Jn1kbHn5fOh48ldkC1U8OAwysdqjP+EtgWL5Kviwq49jwYAdqe9Jwv+FWrlTjc7WF1O2WFmt5WohC d+EHJqwKkTVomxvc2KW56Wx7LFvXqdKol2vaAxUsZYw2f1AlUHnM1J77DZI2VpOOkVe3cZz9ghPWy 4bXiPzrfI/wp2Bug9GUw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iXguF-0002Dd-UG; Thu, 21 Nov 2019 07:29:35 +0000 Received: from mailgw02.mediatek.com ([216.200.240.185]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iXgtz-00020d-Kd; Thu, 21 Nov 2019 07:29:21 +0000 X-UUID: 1ea9954627d44ae4a772b4488c1dc56d-20191120 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Transfer-Encoding:Content-Type:MIME-Version:Message-ID:Date:Subject:CC:To:From; bh=DdOBazdkEY8z3b9oLQBOBsUR+PwkBxvsgtd16bL2wP8=; b=dF7WIzR/p2XrAtxWVR+Uau04hx1SguyHDCvtAL0bumQpo8ZGhIzB07H26eHEYfdMkn2/o/0CgR9ItlVNh8Tz6g35yZIUMZs4km/tPhXQSPOFehPH3nUmb72k9cxTI3ZY5Io2WtdLG+tBJ8+lHghSvJ+oEnk/4FWL1CZdQVzL55o=; X-UUID: 1ea9954627d44ae4a772b4488c1dc56d-20191120 Received: from mtkcas66.mediatek.inc [(172.29.193.44)] by mailgw02.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLS) with ESMTP id 28618728; Wed, 20 Nov 2019 23:29:12 -0800 Received: from mtkmbs05n1.mediatek.inc (172.21.101.15) by MTKMBS62N2.mediatek.inc (172.29.193.42) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Wed, 20 Nov 2019 23:29:32 -0800 Received: from mtkcas08.mediatek.inc (172.21.101.126) by mtkmbs05n1.mediatek.inc (172.21.101.15) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Thu, 21 Nov 2019 15:29:05 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkcas08.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Thu, 21 Nov 2019 15:29:07 +0800 From: Bibby Hsieh To: Jassi Brar , Matthias Brugger , Rob Herring , CK HU Subject: [PATCH] soc: mediatek: cmdq: avoid racing condition with mutex Date: Thu, 21 Nov 2019 15:29:10 +0800 Message-ID: <20191121072910.31665-1-bibby.hsieh@mediatek.com> X-Mailer: git-send-email 2.18.0 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191120_232919_685554_994E055A X-CRM114-Status: UNSURE ( 8.31 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -0.2 (/) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-0.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 0.0 MIME_BASE64_TEXT RAW: Message text disguised using base64 encoding 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.0 UNPARSEABLE_RELAY Informational: message has unparseable relay lines X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, Nicolas Boichat , srv_heupstream@mediatek.com, linux-kernel@vger.kernel.org, Houlong Wei , Dennis-YC Hsieh , linux-mediatek@lists.infradead.org, Bibby Hsieh , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org If cmdq client is multi thread user, racing will occur without mutex protection. It will make the C message queued in mailbox's queue always need D message's triggering. Thread A Thread B Thread C Thread D... ----------------------------------------------------------------------------------- mbox_send_message() send_data() mbox_send_message() *exit mbox_send_message() *exit mbox_client_txdone() tx_tick() mbox_client_txdone() tx_tick() mbox_client_txdone() tx_tick() msg_submit() send_data() msg_submit() *exit msg_submit() *exit ----------------------------------------------------------------------------------- Signed-off-by: Bibby Hsieh --- drivers/soc/mediatek/mtk-cmdq-helper.c | 3 +++ include/linux/soc/mediatek/mtk-cmdq.h | 1 + 2 files changed, 4 insertions(+) diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c index 9add0fd5fa6c..9e35e0beffaa 100644 --- a/drivers/soc/mediatek/mtk-cmdq-helper.c +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c @@ -81,6 +81,7 @@ struct cmdq_client *cmdq_mbox_create(struct device *dev, int index, u32 timeout) client->client.dev = dev; client->client.tx_block = false; client->chan = mbox_request_channel(&client->client, index); + mutex_init(&client->mutex); if (IS_ERR(client->chan)) { long err; @@ -352,9 +353,11 @@ int cmdq_pkt_flush_async(struct cmdq_pkt *pkt, cmdq_async_flush_cb cb, spin_unlock_irqrestore(&client->lock, flags); } + mutex_lock(&client->mutex); mbox_send_message(client->chan, pkt); /* We can send next packet immediately, so just call txdone. */ mbox_client_txdone(client->chan, 0); + mutex_unlock(&client->mutex); return 0; } diff --git a/include/linux/soc/mediatek/mtk-cmdq.h b/include/linux/soc/mediatek/mtk-cmdq.h index a74c1d5acdf3..0f9071cd1bc7 100644 --- a/include/linux/soc/mediatek/mtk-cmdq.h +++ b/include/linux/soc/mediatek/mtk-cmdq.h @@ -28,6 +28,7 @@ struct cmdq_client { struct mbox_chan *chan; struct timer_list timer; u32 timeout_ms; /* in unit of microsecond */ + struct mutex mutex; }; /**