From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932485AbbJ0Nyl (ORCPT ); Tue, 27 Oct 2015 09:54:41 -0400 Received: from mail-qg0-f42.google.com ([209.85.192.42]:34559 "EHLO mail-qg0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932398AbbJ0Nyi (ORCPT ); Tue, 27 Oct 2015 09:54:38 -0400 Subject: Re: [PATCH v2 1/2] serial: 8250_early: do not save and restore IER in write callback To: Masahiro Yamada , linux-serial@vger.kernel.org References: <1445660265-13668-1-git-send-email-yamada.masahiro@socionext.com> <1445660265-13668-2-git-send-email-yamada.masahiro@socionext.com> Cc: Vineet Gupta , Kevin Cernekee , Jiri Slaby , Rob Herring , linux-kernel@vger.kernel.org, Greg Kroah-Hartman From: Peter Hurley Message-ID: <562F821A.90509@hurleysoftware.com> Date: Tue, 27 Oct 2015 09:54:34 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <1445660265-13668-2-git-send-email-yamada.masahiro@socionext.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > --- > > 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. Regards, Peter Hurley > - > - if (ier) > - serial8250_early_out(port, UART_IER, ier); > } > > static void __init init_port(struct earlycon_device *device) >