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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: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Hans de Goede 2017-08-14 22:17:24 +02:00 committed by Wolfram Sang
parent 75fdc51832
commit a5a46bd008
1 changed files with 24 additions and 13 deletions
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37
drivers/i2c/busses/i2c-cht-wc.c
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@ -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;
ret = 0;
mutex_lock(&adap->adap_lock);
if (adap->nack)
return -EIO;
if (read_write == I2C_SMBUS_READ) {
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;