From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46741) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UlxgF-0001Lf-BS for qemu-devel@nongnu.org; Mon, 10 Jun 2013 04:42:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UlxgC-0004e6-GG for qemu-devel@nongnu.org; Mon, 10 Jun 2013 04:42:23 -0400 Received: from mail-bk0-x22c.google.com ([2a00:1450:4008:c01::22c]:35477) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UlxgC-0004e0-9f for qemu-devel@nongnu.org; Mon, 10 Jun 2013 04:42:20 -0400 Received: by mail-bk0-f44.google.com with SMTP id r7so3210970bkg.31 for ; Mon, 10 Jun 2013 01:42:19 -0700 (PDT) From: Peter Wu Date: Mon, 10 Jun 2013 10:42:16 +0200 Message-ID: <1840622.xrNe1LmldJ@al> In-Reply-To: <51B56A71.406@redhat.com> References: <4543955.Y102znvq4W@al> <51B56A71.406@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Subject: Re: [Qemu-devel] [PATCH] chardev: add baud parameter for serial host device List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gerd Hoffmann Cc: Anthony Liguori , qemu-devel@nongnu.org On Monday 10 June 2013 07:56:01 Gerd Hoffmann wrote: > On 06/08/13 23:49, Peter Wu wrote: > > When QEMU starts, it always changes the serial port parameters including > > baud rate. This confused my guest which thought it was outputting at 9600 > > baud while it was in fact changed to 115200. > > > > > > > > After this patch, I can use `-serial /dev/ttyS0,baud=9600` to override the > > default baud rate of 115200. > > I think we should just flip the default to 9600. IIRC this is the > power-on default baud rate of the 8250 uart family, so this should be > the qemu default too. If a guest wants to use a higher baudrate it has > to reprogram the uart anyway (and qemu will apply the guest changes to > the host uart). FWIW, when I tried MODE.COM in ms-dos to change the baud rate, `stty -F /dev/ttyS0 -a` still reported 115200 baud. This is on Linux 3.9 if that matters. Besides this comment, any other feedback on the patch itself? Regards, Peter