On Fri, 18 Sep 2020 at 07:51, Sasha Levin <sashal@xxxxxxxxxx> wrote: > > From: Raviteja Narayanam <raviteja.narayanam@xxxxxxxxxx> > > [ Upstream commit 42e11948ddf68b9f799cad8c0ddeab0a39da33e8 ] > > On some platforms, the log is corrupted while console is being > registered. It is observed that when set_termios is called, there > are still some bytes in the FIFO to be transmitted. > > So, wait for tx_empty inside cdns_uart_console_setup before calling > set_termios. > > Signed-off-by: Raviteja Narayanam <raviteja.narayanam@xxxxxxxxxx> > Reviewed-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx> > Link: https://lore.kernel.org/r/1586413563-29125-2-git-send-email-raviteja.narayanam@xxxxxxxxxx > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> stable rc branch 4.4 arm64 build broken. ../drivers/tty/serial/xilinx_uartps.c: In function ‘cdns_uart_console_setup’: ../drivers/tty/serial/xilinx_uartps.c:1170:40: error: ‘TX_TIMEOUT’ undeclared (first use in this function) 1170 | time_out = jiffies + usecs_to_jiffies(TX_TIMEOUT); ^~~~~~~~~~ Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> > --- > drivers/tty/serial/xilinx_uartps.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c > index 06efcef1b4953..5b4469098888a 100644 > --- a/drivers/tty/serial/xilinx_uartps.c > +++ b/drivers/tty/serial/xilinx_uartps.c > @@ -1152,6 +1152,7 @@ static int cdns_uart_console_setup(struct console *co, char *options) > int bits = 8; > int parity = 'n'; > int flow = 'n'; > + unsigned long time_out; > > if (co->index < 0 || co->index >= CDNS_UART_NR_PORTS) > return -EINVAL; > @@ -1165,6 +1166,13 @@ static int cdns_uart_console_setup(struct console *co, char *options) > if (options) > uart_parse_options(options, &baud, &parity, &bits, &flow); > > + /* Wait for tx_empty before setting up the console */ > + time_out = jiffies + usecs_to_jiffies(TX_TIMEOUT); > + > + while (time_before(jiffies, time_out) && > + cdns_uart_tx_empty(port) != TIOCSER_TEMT) > + cpu_relax(); > + > return uart_set_options(port, co, baud, parity, bits, flow); > } > > -- > 2.25.1 > -- Linaro LKFT https://lkft.linaro.org
