On 10/30/20 10:04 AM, Michael Wu wrote:
Sometimes we would get the following flow when doing an i2cset: 0x1 STATUS SLAVE_ACTIVITY=0x1 : RAW_INTR_STAT=0x514 : INTR_STAT=0x4 I2C_SLAVE_WRITE_RECEIVED 0x1 STATUS SLAVE_ACTIVITY=0x0 : RAW_INTR_STAT=0x714 : INTR_STAT=0x204 I2C_SLAVE_WRITE_REQUESTED I2C_SLAVE_WRITE_RECEIVED Documentation/i2c/slave-interface.rst says that I2C_SLAVE_WRITE_REQUESTED, which is mandatory, should be sent while the data did not arrive yet. It means in a write-request I2C_SLAVE_WRITE_REQUESTED should be reported before any I2C_SLAVE_WRITE_RECEIVED. By the way, I2C_SLAVE_STOP didn't be reported in the above case because DW_IC_INTR_STAT was not 0x200. dev->status can be used to record the current state, especially Designware I2C controller has no interrupts to identify a write-request. This patch makes not only I2C_SLAVE_WRITE_REQUESTED been reported first when IC_INTR_RX_FULL is rising and dev->status isn't STATUS_WRITE_IN_PROGRESS but also I2C_SLAVE_STOP been reported when a STOP condition is received. Signed-off-by: Michael Wu <michael.wu@xxxxxxxxxx> --- drivers/i2c/busses/i2c-designware-slave.c | 45 +++++++++-------------- 1 file changed, 18 insertions(+), 27 deletions(-)
Acked-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
