From edb2c9dd3948738ef030c32b948543e84f4d3f81 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Fri, 27 Mar 2020 23:28:26 +0100 Subject: i2c: altera: use proper variable to hold errno device_property_read_u32() returns errno or 0, so we should use the integer variable 'ret' and not the u32 'val' to hold the retval. Fixes: 0560ad576268 ("i2c: altera: Add Altera I2C Controller driver") Signed-off-by: Wolfram Sang Reviewed-by: Thor Thayer Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-altera.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'drivers/i2c/busses/i2c-altera.c') diff --git a/drivers/i2c/busses/i2c-altera.c b/drivers/i2c/busses/i2c-altera.c index 20ef63820c77..f5c00f903df3 100644 --- a/drivers/i2c/busses/i2c-altera.c +++ b/drivers/i2c/busses/i2c-altera.c @@ -384,7 +384,6 @@ static int altr_i2c_probe(struct platform_device *pdev) struct altr_i2c_dev *idev = NULL; struct resource *res; int irq, ret; - u32 val; idev = devm_kzalloc(&pdev->dev, sizeof(*idev), GFP_KERNEL); if (!idev) @@ -411,17 +410,17 @@ static int altr_i2c_probe(struct platform_device *pdev) init_completion(&idev->msg_complete); spin_lock_init(&idev->lock); - val = device_property_read_u32(idev->dev, "fifo-size", + ret = device_property_read_u32(idev->dev, "fifo-size", &idev->fifo_size); - if (val) { + if (ret) { dev_err(&pdev->dev, "FIFO size set to default of %d\n", ALTR_I2C_DFLT_FIFO_SZ); idev->fifo_size = ALTR_I2C_DFLT_FIFO_SZ; } - val = device_property_read_u32(idev->dev, "clock-frequency", + ret = device_property_read_u32(idev->dev, "clock-frequency", &idev->bus_clk_rate); - if (val) { + if (ret) { dev_err(&pdev->dev, "Default to 100kHz\n"); idev->bus_clk_rate = I2C_MAX_STANDARD_MODE_FREQ; /* default clock rate */ } -- cgit v1.2.3 From 5d4c7977499a736f3f80826bdc9744344ad55589 Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Fri, 8 May 2020 22:12:48 +0900 Subject: i2c: altera: Fix race between xfer_msg and isr thread Use a mutex to protect access to idev->msg_len, idev->buf, etc. which are modified by both altr_i2c_xfer_msg() and altr_i2c_isr(). This is the minimal fix for easy backporting. A cleanup to remove the spinlock will be added later. Signed-off-by: Atsushi Nemoto Acked-by: Thor Thayer [wsa: updated commit message] Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-altera.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'drivers/i2c/busses/i2c-altera.c') diff --git a/drivers/i2c/busses/i2c-altera.c b/drivers/i2c/busses/i2c-altera.c index f5c00f903df3..16ddc26c00e6 100644 --- a/drivers/i2c/busses/i2c-altera.c +++ b/drivers/i2c/busses/i2c-altera.c @@ -70,6 +70,7 @@ * @isr_mask: cached copy of local ISR enables. * @isr_status: cached copy of local ISR status. * @lock: spinlock for IRQ synchronization. + * @isr_mutex: mutex for IRQ thread. */ struct altr_i2c_dev { void __iomem *base; @@ -86,6 +87,7 @@ struct altr_i2c_dev { u32 isr_mask; u32 isr_status; spinlock_t lock; /* IRQ synchronization */ + struct mutex isr_mutex; }; static void @@ -245,10 +247,11 @@ static irqreturn_t altr_i2c_isr(int irq, void *_dev) struct altr_i2c_dev *idev = _dev; u32 status = idev->isr_status; + mutex_lock(&idev->isr_mutex); if (!idev->msg) { dev_warn(idev->dev, "unexpected interrupt\n"); altr_i2c_int_clear(idev, ALTR_I2C_ALL_IRQ); - return IRQ_HANDLED; + goto out; } read = (idev->msg->flags & I2C_M_RD) != 0; @@ -301,6 +304,8 @@ static irqreturn_t altr_i2c_isr(int irq, void *_dev) complete(&idev->msg_complete); dev_dbg(idev->dev, "Message Complete\n"); } +out: + mutex_unlock(&idev->isr_mutex); return IRQ_HANDLED; } @@ -312,6 +317,7 @@ static int altr_i2c_xfer_msg(struct altr_i2c_dev *idev, struct i2c_msg *msg) u32 value; u8 addr = i2c_8bit_addr_from_msg(msg); + mutex_lock(&idev->isr_mutex); idev->msg = msg; idev->msg_len = msg->len; idev->buf = msg->buf; @@ -336,6 +342,7 @@ static int altr_i2c_xfer_msg(struct altr_i2c_dev *idev, struct i2c_msg *msg) altr_i2c_int_enable(idev, imask, true); altr_i2c_fill_tx_fifo(idev); } + mutex_unlock(&idev->isr_mutex); time_left = wait_for_completion_timeout(&idev->msg_complete, ALTR_I2C_XFER_TIMEOUT); @@ -409,6 +416,7 @@ static int altr_i2c_probe(struct platform_device *pdev) idev->dev = &pdev->dev; init_completion(&idev->msg_complete); spin_lock_init(&idev->lock); + mutex_init(&idev->isr_mutex); ret = device_property_read_u32(idev->dev, "fifo-size", &idev->fifo_size); -- cgit v1.2.3