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Commit a5a46bd0 authored by Hans de Goede's avatar Hans de Goede Committed by Wolfram Sang
Browse files

i2c-cht-wc: Add locking to interrupt / smbus_xfer functions 



Although unlikely without locking the smbux_xfer function may miss
the nack flag and further fixes in this patch-set add some more
complex constructions which need protection.

Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 75fdc518

drivers/i2c/busses/i2c-cht-wc.c

+24 −13
Original line number Diff line number Diff line
@@ -47,6 +47,7 @@ struct cht_wc_i2c_adap { 
	struct i2c_adapter adapter;

	wait_queue_head_t wait;

	struct irq_chip irqchip;

	struct mutex adap_lock;

	struct mutex irqchip_lock;

	struct regmap *regmap;

	struct irq_domain *irq_domain;
@@ -63,10 +64,13 @@ static irqreturn_t cht_wc_i2c_adap_thread_handler(int id, void *data) 
	struct cht_wc_i2c_adap *adap = data;

	int ret, reg;



	mutex_lock(&adap->adap_lock);



	/* Read IRQs */

	ret = regmap_read(adap->regmap, CHT_WC_EXTCHGRIRQ, &reg);

	if (ret) {

		dev_err(&adap->adapter.dev, "Error reading extchgrirq reg\n");

		mutex_unlock(&adap->adap_lock);

		return IRQ_NONE;

	}
@@ -80,6 +84,16 @@ static irqreturn_t cht_wc_i2c_adap_thread_handler(int id, void *data) 
	if (ret)

		dev_err(&adap->adapter.dev, "Error writing extchgrirq reg\n");



	if (reg & CHT_WC_EXTCHGRIRQ_ADAP_IRQMASK) {

		adap->nack = !!(reg & CHT_WC_EXTCHGRIRQ_NACK_IRQ);

		adap->done = true;

	}



	mutex_unlock(&adap->adap_lock);



	if (reg & CHT_WC_EXTCHGRIRQ_ADAP_IRQMASK)

		wake_up(&adap->wait);



	/*

	 * Do NOT use handle_nested_irq here, the client irq handler will

	 * likely want to do i2c transfers and the i2c controller uses this
@@ -96,12 +110,6 @@ static irqreturn_t cht_wc_i2c_adap_thread_handler(int id, void *data) 
		local_irq_enable();

	}



	if (reg & CHT_WC_EXTCHGRIRQ_ADAP_IRQMASK) {

		adap->nack = !!(reg & CHT_WC_EXTCHGRIRQ_NACK_IRQ);

		adap->done = true;

		wake_up(&adap->wait);

	}



	return IRQ_HANDLED;

}
@@ -119,8 +127,10 @@ static int cht_wc_i2c_adap_smbus_xfer(struct i2c_adapter *_adap, u16 addr, 
	struct cht_wc_i2c_adap *adap = i2c_get_adapdata(_adap);

	int ret, reg;



	mutex_lock(&adap->adap_lock);

	adap->nack = false;

	adap->done = false;

	mutex_unlock(&adap->adap_lock);



	ret = regmap_write(adap->regmap, CHT_WC_I2C_CLIENT_ADDR, addr);

	if (ret)
@@ -146,18 +156,18 @@ static int cht_wc_i2c_adap_smbus_xfer(struct i2c_adapter *_adap, u16 addr, 
	ret = wait_event_timeout(adap->wait, adap->done, 3 * HZ);

	if (ret == 0)

		return -ETIMEDOUT;

	if (adap->nack)

		return -EIO;



	if (read_write == I2C_SMBUS_READ) {

	ret = 0;

	mutex_lock(&adap->adap_lock);

	if (adap->nack)

		ret = -EIO;

	else if (read_write == I2C_SMBUS_READ) {

		ret = regmap_read(adap->regmap, CHT_WC_I2C_RDDATA, &reg);

		if (ret)

			return ret;



		data->byte = reg;

	}

	mutex_unlock(&adap->adap_lock);



	return 0;

	return ret;

}



static const struct i2c_algorithm cht_wc_i2c_adap_algo = {
@@ -241,6 +251,7 @@ static int cht_wc_i2c_adap_i2c_probe(struct platform_device *pdev) 
		return -ENOMEM;



	init_waitqueue_head(&adap->wait);

	mutex_init(&adap->adap_lock);

	mutex_init(&adap->irqchip_lock);

	adap->irqchip = cht_wc_i2c_irq_chip;

	adap->regmap = pmic->regmap;