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| author | Daniel Kao <daniel.m.kao@gmail.com> | 2022-06-21 15:00:04 -0700 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2022-06-22 00:00:04 +0200 |
| commit | 608404f8742f01d1821a74c5a107e0c62b046423 (patch) | |
| tree | fa68b047ca13c4becb47f0cd8678c88ade60e8ad /platforms/avr/drivers | |
| parent | be42c5fb9885d3bcbf47f99ad6cef343ba2b0b97 (diff) | |
Fix AVR I2C master 1ms timeout (#17174)
* avr i2c_master: Fix 1ms timeout
i2c_start() produces a minimum time_slice of 1ms for use as timeout
value.
The timer granularity is 1ms, it is entirely possible for timer_count
to tick up immediately after the last timer read and falsely trigger
timeout with a '>= 1' comparison.
* avr/drivers/i2c_master: Use timer_elapsed()
Diffstat (limited to 'platforms/avr/drivers')
| -rw-r--r-- | platforms/avr/drivers/i2c_master.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/platforms/avr/drivers/i2c_master.c b/platforms/avr/drivers/i2c_master.c index c1a7b5f72d..524494c99d 100644 --- a/platforms/avr/drivers/i2c_master.c +++ b/platforms/avr/drivers/i2c_master.c @@ -64,7 +64,7 @@ static i2c_status_t i2c_start_impl(uint8_t address, uint16_t timeout) { uint16_t timeout_timer = timer_read(); while (!(TWCR & (1 << TWINT))) { - if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) { + if ((timeout != I2C_TIMEOUT_INFINITE) && (timer_elapsed(timeout_timer) > timeout)) { return I2C_STATUS_TIMEOUT; } } @@ -81,7 +81,7 @@ static i2c_status_t i2c_start_impl(uint8_t address, uint16_t timeout) { timeout_timer = timer_read(); while (!(TWCR & (1 << TWINT))) { - if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) { + if ((timeout != I2C_TIMEOUT_INFINITE) && (timer_elapsed(timeout_timer) > timeout)) { return I2C_STATUS_TIMEOUT; } } @@ -102,7 +102,7 @@ i2c_status_t i2c_start(uint8_t address, uint16_t timeout) { i2c_status_t status; do { status = i2c_start_impl(address, time_slice); - } while ((status < 0) && ((timeout == I2C_TIMEOUT_INFINITE) || (timer_elapsed(timeout_timer) < timeout))); + } while ((status < 0) && ((timeout == I2C_TIMEOUT_INFINITE) || (timer_elapsed(timeout_timer) <= timeout))); return status; } @@ -114,7 +114,7 @@ i2c_status_t i2c_write(uint8_t data, uint16_t timeout) { uint16_t timeout_timer = timer_read(); while (!(TWCR & (1 << TWINT))) { - if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) { + if ((timeout != I2C_TIMEOUT_INFINITE) && (timer_elapsed(timeout_timer) > timeout)) { return I2C_STATUS_TIMEOUT; } } @@ -132,7 +132,7 @@ int16_t i2c_read_ack(uint16_t timeout) { uint16_t timeout_timer = timer_read(); while (!(TWCR & (1 << TWINT))) { - if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) { + if ((timeout != I2C_TIMEOUT_INFINITE) && (timer_elapsed(timeout_timer) > timeout)) { return I2C_STATUS_TIMEOUT; } } @@ -147,7 +147,7 @@ int16_t i2c_read_nack(uint16_t timeout) { uint16_t timeout_timer = timer_read(); while (!(TWCR & (1 << TWINT))) { - if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) { + if ((timeout != I2C_TIMEOUT_INFINITE) && (timer_elapsed(timeout_timer) > timeout)) { return I2C_STATUS_TIMEOUT; } } |