Re: [PATCHv2 2/2] i2c: stm32f7: do not set the STOP condition on error

+Alain (with the correct email address ;-))

Alain, can you have a look a this patch and give your feedback on it.

On my side i tested it on stm32mp157c-ev1 and stm32mp157c-dk2, i didn't see any regression but i prefer to get expert feedback

Thanks Patrice

On 8/15/22 16:52, Jorge Ramirez-Ortiz wrote:

Sending the stop condition without waiting for transfer complete has been found to lock the bus (BUSY) when NACKF is raised.

Tested accessing the NXP SE05X I2C device. https://www.nxp.com/docs/en/application-note/AN12399.pdf

Signed-off-by: Jorge Ramirez-Ortiz jorge@foundries.io Reviewed-by: Oleksandr Suvorov oleksandr.suvorov@foundries.io

---

drivers/i2c/stm32f7_i2c.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/stm32f7_i2c.c b/drivers/i2c/stm32f7_i2c.c index 3a727e68ac..14827e5cec 100644 --- a/drivers/i2c/stm32f7_i2c.c +++ b/drivers/i2c/stm32f7_i2c.c @@ -485,9 +485,11 @@ static int stm32_i2c_message_xfer(struct stm32_i2c_priv *i2c_priv, } }

• /* End of transfer, send stop condition */
• mask = STM32_I2C_CR2_STOP;
• setbits_le32(&regs->cr2, mask);

• if (!ret) {

• /* End of transfer, send stop condition */
  

• mask = STM32_I2C_CR2_STOP;
  

• setbits_le32(&regs->cr2, mask);
  

• }

  return stm32_i2c_check_end_of_message(i2c_priv);

}