Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758863AbYHUVej (ORCPT ); Thu, 21 Aug 2008 17:34:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753042AbYHUVea (ORCPT ); Thu, 21 Aug 2008 17:34:30 -0400 Received: from g4t0017.houston.hp.com ([15.201.24.20]:26459 "EHLO g4t0017.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751085AbYHUVe3 (ORCPT ); Thu, 21 Aug 2008 17:34:29 -0400 From: Bjorn Helgaas To: "Jaswinder Singh" Subject: Re: [Bug #11272] BUG: parport_serial in 2.6.27-rc1 for NetMos Technology PCI 9835 Date: Thu, 21 Aug 2008 15:34:16 -0600 User-Agent: KMail/1.9.9 Cc: "Rafael J. Wysocki" , "Linux Kernel Mailing List" , "Kernel Testers List" , "David Woodhouse" , linux-serial@vger.kernel.org References: <3f9a31f40808092354s3d057effm6ed1d2f506fb4637@mail.gmail.com> In-Reply-To: <3f9a31f40808092354s3d057effm6ed1d2f506fb4637@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200808211534.16465.bjorn.helgaas@hp.com> X-Brightmail-Tracker: AAAAAQAAAAI= X-Whitelist: TRUE Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2314 Lines: 50 On Sunday 10 August 2008 12:54:14 am Jaswinder Singh wrote: > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=11272 > > Subject : BUG: parport_serial in 2.6.27-rc1 for NetMos Technology PCI 9835 > > Submitter : Jaswinder Singh > > Date : 2008-08-05 15:12 (5 days old) > > References : http://marc.info/?l=linux-kernel&m=121794900319776&w=4 > > This problem still exists on 2.6.27-rc2 > > When I connect development boads to /dev/ttyS1 and /dev/ttyS2: > bootloader still prints Junk (Garbage Characters) but when Linux > starts then it becomes readable and normal. > > So I thought problem is in bootloader so I connected different kind of > develepment boards and all shows junk characters during boot-loading. > > But when I connect development boads to /dev/ttyS0 : bootloader > messages are readable and normal with same settings. This sounds like a problem with the port configuration, e.g., baud rate, data bits, etc. I'm a little confused about what's connected to what. I assume you have the consoles of various development boards ("targets") connected to a NetMos card in the host, and you're running conserver or something on the host. And the target bootloader output is garbled, but after the target boots Linux, the output from the target becomes normal? If that's the case, nothing should be changing on the host side that could account for the change from garbled to normal. I notice you're running at 115200. Does the same thing happen if you run at 9600 baud? I'm wondering if the bootloader programs the UART with a divisor that results in a baud rate that's enough different to cause garbling, and when Linux boots, it reprograms the UART with something that matches the NetMos more closely. The builtin ttyS0 and the NetMos ports probably use different clocks, which could explain why it works on one but not the other. There were no changes in parport_serial between 2.6.26 and 2.6.27-rc2. Please confirm whether this is a regression from 2.6.26 or not. Bjorn -- 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/