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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 C0EE4C433E0 for ; Sun, 7 Mar 2021 15:23:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 886A565105 for ; Sun, 7 Mar 2021 15:23:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230327AbhCGPXS (ORCPT ); Sun, 7 Mar 2021 10:23:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42254 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230246AbhCGPXS (ORCPT ); Sun, 7 Mar 2021 10:23:18 -0500 Received: from mail-qk1-x72b.google.com (mail-qk1-x72b.google.com [IPv6:2607:f8b0:4864:20::72b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E7879C06174A; Sun, 7 Mar 2021 07:23:17 -0800 (PST) Received: by mail-qk1-x72b.google.com with SMTP id x10so6932937qkm.8; Sun, 07 Mar 2021 07:23:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ZPQ3DeJRL8XtDGmuX7K2vCZNv7d4zbvPHFELytuIbHk=; b=uvofaxe0GRs3uRjoYWs+Ja0VGYA4ytfA1NjZxKEue9d3DuArYABdzkbbv4sRiDLgcg Nnd4lKyOId8z7Na0AMNzBT/anp8EhsnCPm6UV0WuCdifcTU/T1nzirZxCoR74f+vlNhc zOcBJIUpz3SOBrufb1zAcOUUldmturCSbNiN57y4DPoI5ytOvq9UtSc2Qr3xjVovffEB NqY40vG8pmrhNXEw2SF/ZjJ1tZvwYSmDwFxWrjMV57BYT6OMRsnRo2fB/knKwSN8Q7Fm bTMcFwNoBBMpD/dQCJg1ZXJZSr5EQ+7x6OoQ9zPXDXvnyhf+vW/NE/ZTs9mxMyFTyezQ Kdpg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=ZPQ3DeJRL8XtDGmuX7K2vCZNv7d4zbvPHFELytuIbHk=; b=Fr9l/LdgLfodjqkRaVOs0l6yPg3DQ2YSPYyOdsCefv98Gan+4AI23+4/Qkry5f0RcH dopdpxuq8x4huD7aZEnSUdn5UJCBUDoechoc2l8A3ZcSG4TcWAya/6QlS/MgLpyGtxK/ z6BQNf8F4HW6r6LWsc0ZIszTK2Iu/A7N2o5GXwOVGtv0tY8OQR5QIdbYawSikouQsV+q iQSygLmv8v0ZT65NHiEAKeYWoO8UnfGQvyWXwv/S7D1/2mn4ovWlyei5i2s+jkZx3ksV BckUhVMBafwY0jKy5z1xN5ey4tVe5Pj5fh0ddA+VN1XGFC9k8i/Zou4NW2mpdpGZgpy0 BAJw== X-Gm-Message-State: AOAM531RRM3Cf5b5Zojh/RcQ5DpwXgLcKnPagaJvdbjhFJ91Ae5p67YF sqLC4y2fF762/O/1D3OdreGLxMkvOp5PkKiyosNqjQt/ X-Google-Smtp-Source: ABdhPJwzWdk+YMq0oT+K8PvSrlQNsKsWKJbl7BwPPtXgX+k/1EkARuX+8QtcrysN03VJb2EI1EcxNlkpE25capOx7bM= X-Received: by 2002:a37:46c5:: with SMTP id t188mr17569564qka.47.1615130596833; Sun, 07 Mar 2021 07:23:16 -0800 (PST) MIME-Version: 1.0 References: <20210213122143.19240-1-orsonzhai@gmail.com> <20210213122143.19240-2-orsonzhai@gmail.com> In-Reply-To: <20210213122143.19240-2-orsonzhai@gmail.com> From: Baolin Wang Date: Sun, 7 Mar 2021 23:23:15 +0800 Message-ID: Subject: Re: [PATCH v2 1/3] mailbox: sprd: Introduce refcnt when clients requests/free channels To: Orson Zhai Cc: Rob Herring , Chunyan Zhang , Jassi Brar , Mark Brown , Devicetree List , LKML , Haidong Yao , Orson Zhai Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Sat, Feb 13, 2021 at 8:22 PM Orson Zhai wrote: > > From: Orson Zhai > > 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 Sorry for the late reply. LGTM. Reviewed-by: Baolin Wang > --- > 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 f6fab24ae8a9..920de7b9dce1 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 > -- > 2.17.1 > -- Baolin Wang