From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754812AbaAUOza (ORCPT ); Tue, 21 Jan 2014 09:55:30 -0500 Received: from gloria.sntech.de ([95.129.55.99]:49439 "EHLO gloria.sntech.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754606AbaAUOz2 convert rfc822-to-8bit (ORCPT ); Tue, 21 Jan 2014 09:55:28 -0500 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Greg Kroah-Hartman Cc: Jiri Slaby , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org, Kukjin Kim , Chander Kashyap Subject: Re: [PATCH] serial: samsung: move clock deactivation below uart registration Date: Tue, 21 Jan 2014 15:26:42 +0100 Message-ID: <2813762.7GxfVBIcrq@phil> User-Agent: KMail/4.11.3 (Linux/3.11-2-amd64; KDE/4.11.3; x86_64; ; ) In-Reply-To: <201312050054.39327.heiko@sntech.de> References: <201312050054.39327.heiko@sntech.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="iso-8859-1" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Greg, just wanted to ask about the state of this patch. I can see it in your branch named "fixes" [0] but it seems it hasn't made its way into the kernel neither during the 3.13-rcs or with your 3.14-pull [1]. Thanks Heiko [0] https://git.kernel.org/cgit/linux/kernel/git/gregkh/tty.git/log/?h=fixes [1] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=bcee63488ece9a0fca8be19951428a7b41001e66 Am Donnerstag, 5. Dezember 2013, 00:54:38 schrieb Heiko Stübner: > Commit 60e93575476f (serial: samsung: enable clock before clearing pending > interrupts during init) added handling of the controller clock during init. > > On most systems this clock is also one of the baud_clock sources and > possibly used by the earlycon and thus already enabled by the bootloader. > > Therefore a gap exists between s3c24xx_serial_init_port disabling the > clock and an attached console reenabling it, making the transition from > earlycon to regular console possibly hang the system - as seen on my > S3C2442 based Freerunner today. > > Therefore move the disabling of the clock from s3c24xx_serial_init_port > below the uart port registration, effectively creating an overlap and > keeping the clock running non-stop if the console wants to grab this port. > > Signed-off-by: Heiko Stuebner > --- > drivers/tty/serial/samsung.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c > index c1af04d..9cd706d 100644 > --- a/drivers/tty/serial/samsung.c > +++ b/drivers/tty/serial/samsung.c > @@ -1209,7 +1209,6 @@ static int s3c24xx_serial_init_port(struct > s3c24xx_uart_port *ourport, > > /* reset the fifos (and setup the uart) */ > s3c24xx_serial_resetport(port, cfg); > - clk_disable_unprepare(ourport->clk); > return 0; > } > > @@ -1287,6 +1286,13 @@ static int s3c24xx_serial_probe(struct > platform_device *pdev) uart_add_one_port(&s3c24xx_uart_drv, > &ourport->port); > platform_set_drvdata(pdev, &ourport->port); > > + /* > + * Deactivate the clock enabled in s3c24xx_serial_init_port here, > + * so that a potential re-enablement through the pm-callback overlaps > + * and keeps the clock enabled in this case. > + */ > + clk_disable_unprepare(ourport->clk); > + > #ifdef CONFIG_SAMSUNG_CLOCK > ret = device_create_file(&pdev->dev, &dev_attr_clock_source); > if (ret < 0)