2015-10-28 23:36 GMT+09:00 Peter Hurley <[email protected]>: > On 10/27/2015 11:27 PM, Masahiro Yamada wrote: >> Hi Peter, >> >> 2015-10-27 22:54 GMT+09:00 Peter Hurley <[email protected]>: >>> Hi Masahiro, >>> >>> On 10/24/2015 12:17 AM, Masahiro Yamada wrote: >>>> The IER has already been masked in early_serial8250_setup(), there is >>>> no reason to save and restore it every time early_serial8250_write() >>>> is called. >>>> >>>> Signed-off-by: Masahiro Yamada <[email protected]> >>>> --- >>>> >>>> drivers/tty/serial/8250/8250_early.c | 12 ------------ >>>> 1 file changed, 12 deletions(-) >>>> >>>> diff --git a/drivers/tty/serial/8250/8250_early.c >>>> b/drivers/tty/serial/8250/8250_early.c >>>> index 7aff3d8..559b681 100644 >>>> --- a/drivers/tty/serial/8250/8250_early.c >>>> +++ b/drivers/tty/serial/8250/8250_early.c >>>> @@ -99,20 +99,8 @@ static void __init early_serial8250_write(struct >>>> console *console, >>>> { >>>> struct earlycon_device *device = console->data; >>>> struct uart_port *port = &device->port; >>>> - unsigned int ier; >>>> - >>>> - /* Save the IER and disable interrupts preserving the UUE bit */ >>>> - ier = serial8250_early_in(port, UART_IER); >>>> - if (ier) >>>> - serial8250_early_out(port, UART_IER, ier & UART_IER_UUE); >>>> >>>> uart_console_write(port, s, count, serial_putc); >>> >>> >>> >>>> - >>>> - /* Wait for transmitter to become empty and restore the IER */ >>>> - wait_for_xmitr(port); >>> >>> This wait_for_xmitr() change needs to be in patch 2/2. >>> >> >> >> Why? > > Because if someone reports a regression bisected to this commit, > we won't know if the regression is because we're not saving/restoring IER > or because the transmitter is still running. >
Good point. I will send v3. Thanks! -- Best Regards Masahiro Yamada -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
