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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 405C1C43617 for ; Wed, 12 May 2021 16:19:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 24CD361D68 for ; Wed, 12 May 2021 16:19:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240485AbhELQSK (ORCPT ); Wed, 12 May 2021 12:18:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:48856 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235020AbhELPfI (ORCPT ); Wed, 12 May 2021 11:35:08 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CA1F761C37; Wed, 12 May 2021 15:17:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620832661; bh=8TVqaRWtXkycjf8XmVkiEBiZDcz3aCqEO5QImUkOQGc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=g8U0g7nJcVGzSRcymIPX+pQMc5WEMkOa+XFeXDOZOJbBks46ONkS3nKHyzKb7dzvV XyxXEXco6cibTWYynQK7MTn89rN4hRiKbvlFGhSqgBb0GdFT0MjR8Kk+6IZS8Dxp2m l7sEPmunm0/+7L54GgXi+4a7LyWrHLdOn1ddUjHI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Orson Zhai , Baolin Wang , Jassi Brar , Sasha Levin Subject: [PATCH 5.10 336/530] mailbox: sprd: Introduce refcnt when clients requests/free channels Date: Wed, 12 May 2021 16:47:26 +0200 Message-Id: <20210512144830.845105746@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210512144819.664462530@linuxfoundation.org> References: <20210512144819.664462530@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Orson Zhai [ Upstream commit 9468ab84032f96496e998cfa173cd1d0ac316bcd ] Unisoc mailbox has no way to be enabled/disabled for any single channel. They can only be set to startup or shutdown as a whole device at same time. Add a variable to count references to avoid mailbox FIFO being reset unexpectedly when clients are requesting or freeing channels. Also add a lock to dismiss possible conflicts from register r/w in different startup or shutdown threads. And fix the crash problem when early interrupts come from channel which has not been requested by client yet. Fixes: ca27fc26cd22 ("mailbox: sprd: Add Spreadtrum mailbox driver") Signed-off-by: Orson Zhai Reviewed-by: Baolin Wang Signed-off-by: Jassi Brar Signed-off-by: Sasha Levin --- drivers/mailbox/sprd-mailbox.c | 43 +++++++++++++++++++++++----------- 1 file changed, 29 insertions(+), 14 deletions(-) diff --git a/drivers/mailbox/sprd-mailbox.c b/drivers/mailbox/sprd-mailbox.c index 4c325301a2fe..94d9067dc8d0 100644 --- a/drivers/mailbox/sprd-mailbox.c +++ b/drivers/mailbox/sprd-mailbox.c @@ -60,6 +60,8 @@ struct sprd_mbox_priv { struct clk *clk; u32 outbox_fifo_depth; + struct mutex lock; + u32 refcnt; struct mbox_chan chan[SPRD_MBOX_CHAN_MAX]; }; @@ -115,7 +117,11 @@ static irqreturn_t sprd_mbox_outbox_isr(int irq, void *data) id = readl(priv->outbox_base + SPRD_MBOX_ID); chan = &priv->chan[id]; - mbox_chan_received_data(chan, (void *)msg); + if (chan->cl) + mbox_chan_received_data(chan, (void *)msg); + else + dev_warn_ratelimited(priv->dev, + "message's been dropped at ch[%d]\n", id); /* Trigger to update outbox FIFO pointer */ writel(0x1, priv->outbox_base + SPRD_MBOX_TRIGGER); @@ -215,18 +221,22 @@ static int sprd_mbox_startup(struct mbox_chan *chan) struct sprd_mbox_priv *priv = to_sprd_mbox_priv(chan->mbox); u32 val; - /* Select outbox FIFO mode and reset the outbox FIFO status */ - writel(0x0, priv->outbox_base + SPRD_MBOX_FIFO_RST); + mutex_lock(&priv->lock); + if (priv->refcnt++ == 0) { + /* Select outbox FIFO mode and reset the outbox FIFO status */ + writel(0x0, priv->outbox_base + SPRD_MBOX_FIFO_RST); - /* Enable inbox FIFO overflow and delivery interrupt */ - val = readl(priv->inbox_base + SPRD_MBOX_IRQ_MSK); - val &= ~(SPRD_INBOX_FIFO_OVERFLOW_IRQ | SPRD_INBOX_FIFO_DELIVER_IRQ); - writel(val, priv->inbox_base + SPRD_MBOX_IRQ_MSK); + /* Enable inbox FIFO overflow and delivery interrupt */ + val = readl(priv->inbox_base + SPRD_MBOX_IRQ_MSK); + val &= ~(SPRD_INBOX_FIFO_OVERFLOW_IRQ | SPRD_INBOX_FIFO_DELIVER_IRQ); + writel(val, priv->inbox_base + SPRD_MBOX_IRQ_MSK); - /* Enable outbox FIFO not empty interrupt */ - val = readl(priv->outbox_base + SPRD_MBOX_IRQ_MSK); - val &= ~SPRD_OUTBOX_FIFO_NOT_EMPTY_IRQ; - writel(val, priv->outbox_base + SPRD_MBOX_IRQ_MSK); + /* Enable outbox FIFO not empty interrupt */ + val = readl(priv->outbox_base + SPRD_MBOX_IRQ_MSK); + val &= ~SPRD_OUTBOX_FIFO_NOT_EMPTY_IRQ; + writel(val, priv->outbox_base + SPRD_MBOX_IRQ_MSK); + } + mutex_unlock(&priv->lock); return 0; } @@ -235,9 +245,13 @@ static void sprd_mbox_shutdown(struct mbox_chan *chan) { struct sprd_mbox_priv *priv = to_sprd_mbox_priv(chan->mbox); - /* Disable inbox & outbox interrupt */ - writel(SPRD_INBOX_FIFO_IRQ_MASK, priv->inbox_base + SPRD_MBOX_IRQ_MSK); - writel(SPRD_OUTBOX_FIFO_IRQ_MASK, priv->outbox_base + SPRD_MBOX_IRQ_MSK); + mutex_lock(&priv->lock); + if (--priv->refcnt == 0) { + /* Disable inbox & outbox interrupt */ + writel(SPRD_INBOX_FIFO_IRQ_MASK, priv->inbox_base + SPRD_MBOX_IRQ_MSK); + writel(SPRD_OUTBOX_FIFO_IRQ_MASK, priv->outbox_base + SPRD_MBOX_IRQ_MSK); + } + mutex_unlock(&priv->lock); } static const struct mbox_chan_ops sprd_mbox_ops = { @@ -266,6 +280,7 @@ static int sprd_mbox_probe(struct platform_device *pdev) return -ENOMEM; priv->dev = dev; + mutex_init(&priv->lock); /* * The Spreadtrum mailbox uses an inbox to send messages to the target -- 2.30.2