Performing i2c write operation while SDA or SCL line is held or grounded by slave device, we go into infinite at91_twi_write_next_byte loop with TXRDY interrupt spam.
Signed-off-by: Raag Jadav <[email protected]> --- drivers/i2c/busses/i2c-at91.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c index 3f3e8b3..b2f5fdb 100644 --- a/drivers/i2c/busses/i2c-at91.c +++ b/drivers/i2c/busses/i2c-at91.c @@ -72,6 +72,7 @@ #define AT91_TWI_TXCOMP BIT(0) /* Transmission Complete */ #define AT91_TWI_RXRDY BIT(1) /* Receive Holding Register Ready */ #define AT91_TWI_TXRDY BIT(2) /* Transmit Holding Register Ready */ +#define AT91_TWI_SVREAD BIT(3) /* Slave Read */ #define AT91_TWI_OVRE BIT(6) /* Overrun Error */ #define AT91_TWI_UNRE BIT(7) /* Underrun Error */ #define AT91_TWI_NACK BIT(8) /* Not Acknowledged */ @@ -571,7 +572,10 @@ static irqreturn_t atmel_twi_interrupt(int irq, void *dev_id) at91_disable_twi_interrupts(dev); complete(&dev->cmd_complete); } else if (irqstatus & AT91_TWI_TXRDY) { - at91_twi_write_next_byte(dev); + if ((status & AT91_TWI_SVREAD) && (dev->buf_len == 0)) + at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_TXRDY); + else + at91_twi_write_next_byte(dev); } /* catch error flags */ -- 2.7.4
