From 9468ab84032f96496e998cfa173cd1d0ac316bcd Mon Sep 17 00:00:00 2001 From: Orson Zhai Date: Fri, 19 Mar 2021 14:15:35 +0800 Subject: mailbox: sprd: Introduce refcnt when clients requests/free channels 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 --- drivers/mailbox/sprd-mailbox.c | 43 ++++++++++++++++++++++++++++-------------- 1 file changed, 29 insertions(+), 14 deletions(-) (limited to 'drivers/mailbox') diff --git a/drivers/mailbox/sprd-mailbox.c b/drivers/mailbox/sprd-mailbox.c index 56b34a67ff1a..be0bca9837c4 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 -- cgit v1.2.3