On 10/11/2017 01:53 PM, Radoslaw Pietrzyk wrote: > Do not read data on RXNE but on BTF only due to HW > synchronisation problems and NACKing read data too early. > It was found during testing of stmpe811 touchscreen driver. >
Would you mind to explain what is behind "hw sync issue" you've seen ? > Signed-off-by: Radoslaw Pietrzyk <radoslaw.pietr...@gmail.com> > --- > drivers/i2c/busses/i2c-stm32f4.c | 11 +---------- > 1 file changed, 1 insertion(+), 10 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-stm32f4.c > b/drivers/i2c/busses/i2c-stm32f4.c > index 4ec1084..86bcf4c 100644 > --- a/drivers/i2c/busses/i2c-stm32f4.c > +++ b/drivers/i2c/busses/i2c-stm32f4.c > @@ -409,16 +409,9 @@ static void stm32f4_i2c_handle_read(struct > stm32f4_i2c_dev *i2c_dev) > * So, here we just disable buffer interrupt in order to avoid another > * system preemption due to RX not empty event. > */ > - case 2: > - case 3: > + default: > stm32f4_i2c_clr_bits(reg, STM32F4_I2C_CR2_ITBUFEN); > break; > - /* > - * For N byte reception with N > 3 we directly read data register > - * until N-2 data. > - */ > - default: > - stm32f4_i2c_read_msg(i2c_dev); > } > } > > @@ -470,8 +463,6 @@ static void stm32f4_i2c_handle_rx_done(struct > stm32f4_i2c_dev *i2c_dev) > */ > reg = i2c_dev->base + STM32F4_I2C_CR1; > stm32f4_i2c_clr_bits(reg, STM32F4_I2C_CR1_ACK); > - stm32f4_i2c_read_msg(i2c_dev); > - break; > default: > stm32f4_i2c_read_msg(i2c_dev); > } >
