On Wed, 11 Jan 2023 at 09:08, Pali Rohár <p...@kernel.org> wrote: > > On Wednesday 11 January 2023 08:53:30 Loic Poulain wrote: > > On Wed, 11 Jan 2023 at 00:53, Pali Rohár <p...@kernel.org> wrote: > > > > > > On Tuesday 10 January 2023 20:24:06 Loic Poulain wrote: > > > > The u-boot console may show some corrupted characters when > > > > printing in board_init() due to reset of the UART (probe) > > > > before the TX FIFO has been completely drained. > > > > > > > > To fix this issue, and in case UART is still running, we now > > > > try to flush the FIFO before proceeding to UART reinitialization. > > > > For this we're waiting for Transmitter Complete bit, indicating > > > > that the FIFO and the shift register are empty. > > > > > > > > flushing has a 4ms timeout guard, which is normally more than > > > > enough to consume the FIFO @ low baudrate (9600bps). > > > > > > > > Signed-off-by: Loic Poulain <loic.poul...@linaro.org> > > > > Tested-by: Lothar Waßmann <l...@karo-electronics.de> > > > > > > Hello! Last time when I looked at this driver I was in impression that > > > also _mxc_serial_setbrg() function requires calling some flush function > > > at the beginning. Could you please check if it is needed or not? I'm > > > really not sure. > > > > _mxc_serial_setbrg is usually called after init, which now includes that > > flush. > > I'm looking at it and this function is called also from > mxc_serial_setbrg() callback, which is used by u-boot to change baudrate > after the init.
Ok, good point, then it makes sense to add this guard here as well.
