Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753096AbXE3Bt3 (ORCPT ); Tue, 29 May 2007 21:49:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751496AbXE3Bse (ORCPT ); Tue, 29 May 2007 21:48:34 -0400 Received: from nwk-ea-fw-1.sun.com ([192.18.42.249]:30469 "EHLO nwk-ea-fw-1.sun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750824AbXE3Bsc (ORCPT ); Tue, 29 May 2007 21:48:32 -0400 Date: Tue, 29 May 2007 18:45:57 -0700 From: Yinghai Lu Subject: [PATCH 5/5] serial: set DTR in uart for kernel serial console To: Andrew Morton , Andi Kleen , Bjorn Helgaas , Russell King Cc: Linux Kernel Mailing List Reply-to: Yinghai Lu Message-id: <200705291845.57949.yinghai.lu@sun.com> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7BIT Content-disposition: inline User-Agent: KMail/1.8.2 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1389 Lines: 38 [PATCH 5/5] 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/serial_core.c b/drivers/serial/serial_core.c index 326020f..bec5eb5 100644 --- a/drivers/serial/serial_core.c +++ b/drivers/serial/serial_core.c @@ -2303,8 +2303,14 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port) * It may be that the port was not available. */ if (port->type != PORT_UNKNOWN && - port->cons && !(port->cons->flags & CON_ENABLED)) + port->cons && !(port->cons->flags & CON_ENABLED)) { + /* + * some uarts on other side don't support no flow control. + * So we set DTR in host uart to make them happy --- YHLU + */ + port->mctrl |= TIOCM_DTR; register_console(port->cons); + } /* * Ensure UPF_DEAD is not set. - 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/