>-----Original Message----- >From: Greg Kroah-Hartman [mailto:gregkh@xxxxxxxxxxxxxxxxxxx] >Sent: Friday, November 16, 2012 9:00 AM >To: Sonic Zhang >Cc: linux-serial@xxxxxxxxxxxxxxx; uclinux-dist-devel@xxxxxxxxxxxxxxxxxxxx; Zhang, >Sonic >Subject: Re: [PATCH] serial: bfin_uart: Don't switch baud rate untill the transfer >buffer is empty. > >On Wed, Nov 07, 2012 at 12:55:42PM +0800, Sonic Zhang wrote: >> From: Sonic Zhang <sonic.zhang@xxxxxxxxxx> >> >> set_termios may be invoked before the former data transfer is >> completed. Block until the tranfer is done. >> >> Signed-off-by: Sonic Zhang <sonic.zhang@xxxxxxxxxx> >> --- >> drivers/tty/serial/bfin_uart.c | 4 ++++ >> 1 files changed, 4 insertions(+), 0 deletions(-) >> >> diff --git a/drivers/tty/serial/bfin_uart.c >> b/drivers/tty/serial/bfin_uart.c index 9242d56..71c0c09 100644 >> --- a/drivers/tty/serial/bfin_uart.c >> +++ b/drivers/tty/serial/bfin_uart.c >> @@ -869,6 +869,10 @@ bfin_serial_set_termios(struct uart_port *port, >> struct ktermios *termios, >> >> UART_SET_ANOMALY_THRESHOLD(uart, USEC_PER_SEC / baud * 15); >> >> + /* Wait till the transfer buffer is empty */ >> + while (UART_GET_GCTL(uart) & UCEN && !(UART_GET_LSR(uart) & >TEMT)) >> + barrier(); > >Where is the "the hardware is hung" break out of this loop? > Sorry, I will add time_after check soon. Regards, Sonic >And why "barrier()"? > >thanks, > >greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
