diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c index 4fc471ce173e..cb418140cbbe 100644 --- a/drivers/i2c/busses/i2c-octeon.c +++ b/drivers/i2c/busses/i2c-octeon.c @@ -109,6 +109,8 @@ #define TWSI_INT_SDA BIT_ULL(10) #define TWSI_INT_SCL BIT_ULL(11) +#define I2C_OCTEON_EVENT_WAIT 80 /* microseconds */ + struct octeon_i2c { wait_queue_head_t queue; struct i2c_adapter adap; @@ -339,11 +341,29 @@ static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id) return IRQ_HANDLED; } -static int octeon_i2c_test_iflg(struct octeon_i2c *i2c) +static bool octeon_i2c_test_iflg(struct octeon_i2c *i2c) { return (octeon_i2c_ctl_read(i2c) & TWSI_CTL_IFLG); } +static bool octeon_i2c_test_ready(struct octeon_i2c *i2c, bool *first) +{ + if (octeon_i2c_test_iflg(i2c)) + return true; + + if (*first) { + *first = false; + return false; + } + + /* + * IRQ has signaled an event but IFLG hasn't changed. + * Sleep and retry once. + */ + usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT); + return octeon_i2c_test_iflg(i2c); +} + /** * octeon_i2c_wait - wait for the IFLG to be set * @i2c: The struct octeon_i2c @@ -353,15 +373,14 @@ static int octeon_i2c_test_iflg(struct octeon_i2c *i2c) static int octeon_i2c_wait(struct octeon_i2c *i2c) { long time_left; + bool first = 1; i2c->int_enable(i2c); - time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_iflg(i2c), + time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_ready(i2c, &first), i2c->adap.timeout); i2c->int_disable(i2c); - if (!time_left) { - dev_dbg(i2c->dev, "%s: timeout\n", __func__); + if (!time_left) return -ETIMEDOUT; - } return 0; } @@ -427,11 +446,28 @@ static int octeon_i2c_check_status(struct octeon_i2c *i2c, int final_read) } } -static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c) +static bool octeon_i2c_hlc_test_valid(struct octeon_i2c *i2c) { - u64 val = __raw_readq(i2c->twsi_base + SW_TWSI); + return (__raw_readq(i2c->twsi_base + SW_TWSI) & SW_TWSI_V) == 0; +} - return (val & SW_TWSI_V) == 0; +static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c, bool *first) +{ + /* check if valid bit is cleared */ + if (octeon_i2c_hlc_test_valid(i2c)) + return true; + + if (*first) { + *first = false; + return false; + } + + /* + * IRQ has signaled an event but valid bit isn't cleared. + * Sleep and retry once. + */ + usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT); + return octeon_i2c_hlc_test_valid(i2c); } static void octeon_i2c_hlc_int_enable(struct octeon_i2c *i2c) @@ -453,11 +489,12 @@ static void octeon_i2c_hlc_int_clear(struct octeon_i2c *i2c) */ static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c) { + bool first = 1; int time_left; i2c->hlc_int_enable(i2c); time_left = wait_event_timeout(i2c->queue, - octeon_i2c_hlc_test_ready(i2c), + octeon_i2c_hlc_test_ready(i2c, &first), i2c->adap.timeout); i2c->hlc_int_disable(i2c); if (!time_left) {