Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932227AbXBSNaG (ORCPT ); Mon, 19 Feb 2007 08:30:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932225AbXBSNaG (ORCPT ); Mon, 19 Feb 2007 08:30:06 -0500 Received: from ug-out-1314.google.com ([66.249.92.171]:47270 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932227AbXBSNaC (ORCPT ); Mon, 19 Feb 2007 08:30:02 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:date:from:to:cc:subject:message-id:mime-version:content-type:content-disposition:user-agent:sender; b=QIopT3XCM6zUAsfw1xDwlvZkr30V7tcFOp0lcB95nsDqKc1FhnhrdoAC64PbWPLc/pTLQKFg0BUBGzAVi4NMmPsI3j+klayZ0a4YOjGLWhbGp3dBnYGK2gdGU4BBXa24zejxmK73QuREAB3ZwqSYspUwzq2dcjFbLH+Bf4giqJY= Date: Tue, 20 Feb 2007 13:29:09 +0000 From: Frederik Deweerdt To: rmk+lkml@arm.linux.org.uk Cc: jose.goncalves@inov.pt, tie-fei.zang@freescale.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org Subject: Serial related oops Message-ID: <20070220132909.GD566@slug> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: mutt-ng/devel-r804 (Linux) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1519 Lines: 48 (Sorry for the resend, I forgot to cc the list) Hi Russell, It seems that the following change in drivers/serial/8250.c + + /* + * Do a quick test to see if we receive an + * interrupt when we enable the TX irq. + */ + serial_outp(up, UART_IER, UART_IER_THRI); + lsr = serial_in(up, UART_LSR); + iir = serial_in(up, UART_IIR); + serial_outp(up, UART_IER, 0); + + if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) { + if (!(up->capabilities & UART_BUG_TXEN)) { + up->capabilities |= UART_BUG_TXEN; + pr_debug("ttyS%d - enabling bad tx status workarounds\n", + port->line); + } + } else { + up->capabilities &= ~UART_BUG_TXEN; + } + that was introduced in 2.6.12[1], is causing oopses on some hardware. In particular Jose Goncalves reported[2] an oops in 2.6.16.38 reproducible (after a few days of open()/close() on the serial port). He bisected this to that change -thanks for the long debugging Jose ;)-. and reverting that part of the 2.6.12 git patch seems to fix the problem. I was wondering: - what is the goal of the test? - could this be CONFIGed ? Regards, Frederik PS: CCing Andrew and Zang Roy-r61911 as they seemed to discuss this in http://lkml.org/lkml/2006/6/13/21 [1]http://lkml.org/lkml/2005/6/23/266 [2]http://lkml.org/lkml/2007/1/26/157 - 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/