From: Orson Zhai orson.zhai@unisoc.com
[ 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 orson.zhai@unisoc.com Reviewed-by: Baolin Wang baolin.wang7@gmail.com Signed-off-by: Jassi Brar jaswinder.singh@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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