Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757295AbXEOUuq (ORCPT ); Tue, 15 May 2007 16:50:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753089AbXEOUui (ORCPT ); Tue, 15 May 2007 16:50:38 -0400 Received: from nwk-ea-fw-1.sun.com ([192.18.42.249]:25171 "EHLO nwk-ea-fw-1.sun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754526AbXEOUuh (ORCPT ); Tue, 15 May 2007 16:50:37 -0400 Date: Tue, 15 May 2007 13:48:14 -0700 From: Yinghai Lu Subject: [PATCH] serial: set DTR in uart for kernel serial console In-reply-to: <4648B2CC.2020403@sun.com> To: Andrew Morton , Andi Kleen , bjorn.helgaas@hp.com, rmk@arm.linux.org.uk Cc: Linux Kernel Mailing List , Yinghai.Lu@Sun.COM Reply-to: Yinghai Lu Message-id: <200705151348.15355.yinghai.lu@sun.com> MIME-version: 1.0 Content-type: text/plain; charset=iso-8859-1 Content-transfer-encoding: 7BIT Content-disposition: inline References: <86802c440705122233y327756e7te534199f46b2059d@mail.gmail.com> <20070514181007.GA29682@flint.arm.linux.org.uk> <4648B2CC.2020403@sun.com> User-Agent: KMail/1.8.2 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1239 Lines: 38 Hope format is OK. Sending with KMail Message/Insert File YH [PATCH] serial: set DTR in uart for kernel serial console Some UARTs on other side need host uart DTR is set, otherwise will not receive char from the host that kernel is runing during kernel boot stage. BTW: earlyprintk and early_uart are hard coded to set DTR/RTS. Signed-off-by: Yinghai Lu Cc: Russell King Cc: Andi Kleen Cc: Bjorn Helgaas diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 48e259a..a925547 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -2397,6 +2397,11 @@ static void __init serial8250_isa_init_ports(void) up->mcr_force = ALPHA_KLUDGE_MCR; up->port.ops = &serial8250_pops; + + /* some uarts on other side don't support no flow control. So we set + * DTR in host uart to make them happy --- YHLU + */ + up->port.mctrl |= TIOCM_DTR; } for (i = 0, up = serial8250_ports; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/