Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935196Ab3DIGAE (ORCPT ); Tue, 9 Apr 2013 02:00:04 -0400 Received: from mail-pd0-f181.google.com ([209.85.192.181]:57276 "EHLO mail-pd0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933440Ab3DIGAC convert rfc822-to-8bit (ORCPT ); Tue, 9 Apr 2013 02:00:02 -0400 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 6.3 \(1503\)) Subject: Re: [RFC PATCH arm: initial TI-Nspire support] From: Daniel Tang In-Reply-To: Date: Tue, 9 Apr 2013 15:59:52 +1000 Cc: "Arnd Bergmann" , linux-arm-kernel@lists.infradead.org, linux@arm.linux.org.uk, "Lionel Debroux" , linux-kernel@vger.kernel.org, "Linus Walleij" Content-Transfer-Encoding: 8BIT Message-Id: <29D8E742-C870-45AE-B102-13A477AE6419@gmail.com> References: <6FE4B33E-A503-4A75-AEED-831CB2C06D83@gmail.com> <4B3FD561-84FC-40CD-B747-13851692D673@gmail.com> <521DFDFC-7E9E-47EA-ACDA-C91BBDC8454E@gmail.com> <201304072323.42173.arnd@arndb.de> <896CB251-17FC-4327-BA4E-A8FD9ED1BEC7@gmail.com> To: Fabian Vogt X-Mailer: Apple Mail (2.1503) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1520 Lines: 23 On 09/04/2013, at 5:16 AM, Fabian Vogt wrote: > The latest kernel it seems to get stuck at > console_lock() in register_framebuffer (drivers/video/fbmem.c:1655) > if the LCD-controller is enabled. (Early printk and serial console works fine) > CONFIG_NO_HZ is not activated, it works completely. > Could this be a kernel bug or is this an issue with our timer configuration? Even with the CONFIG_NO_HZ option disabled, I've found that probing of our LCD hardware sometimes still fail with an error of -2. Depending on how I arrange the device tree or the contents of the boot arguments or, as said, the CONFIG_NO_HZ option, I get different behaviours ranging from: * Getting a -2 error during device probe (possibly due to a clock not being found). * LCD hardware is found but boot hangs right after the driver is initialised. * LCD hardware is apparently initialised correctly and text appears onscreen but user mode init hangs and I never get to a shell prompt. This smells of a race condition that occurs before the clcd driver even gets to initialise. Some bug in our timer code? A OF or console bug perhaps? Though, I'm a bit hesitant to blame it on a kernel subsystem bug until it's clear that our code isn't at fault. Any suggestions?-- 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/