Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753417Ab1EJGQ4 (ORCPT ); Tue, 10 May 2011 02:16:56 -0400 Received: from mail-iy0-f174.google.com ([209.85.210.174]:59062 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750885Ab1EJGQz (ORCPT ); Tue, 10 May 2011 02:16:55 -0400 Message-ID: From: "Subhasish Ghosh" To: "Alan Cox" Cc: , "Greg Kroah-Hartman" , , , , , "Andrew Morton \(commit_signer:1/4=25%\)" , "Randy Dunlap \(commit_signer:1/4=25%\)" , "open list" References: <1303474109-6212-1-git-send-email-subhasish@mistralsolutions.com><1303474109-6212-9-git-send-email-subhasish@mistralsolutions.com><034A6447E0D54737B5CEE009A4D20B37@subhasishg><20110509144610.6b4f7090@lxorguk.ukuu.org.uk><3A9C5CD56396439DBF825BB4E5779DB9@subhasishg> <20110509145534.2677dfa1@lxorguk.ukuu.org.uk> In-Reply-To: <20110509145534.2677dfa1@lxorguk.ukuu.org.uk> Subject: Re: [PATCH v4 08/11] tty: add pruss SUART driver Date: Tue, 10 May 2011 11:47:02 +0530 Organization: Mistral Solutions MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2659 Lines: 72 Hi Alan, >> >> I then modified this function to as follows and the error is not >> >> observed >> >> anymore. >> > >> > That looks like you are somehow calling uart_carrier_raised somewhere >> > with interrupts disabled ? >> > >> I am not calling this function in my driver atall, this is getting called >> by >> tty_port.c > > Can you verify the status of the interrupt flags at the point that > routine is called in your code and get a backtrace of the path. It > should never be gettng called with interrupts off, and if it is we need > to know what the path is. Otherwise that code change would imply a bug > in the core code for the platform which seems less likely. Here is the back trace: root@arago:~# ------------[ cut here ]------------ WARNING: at drivers/tty/serial/pruss_suart.c:295 uart_carrier_raised+0x2c/0x74() Modules linked in: pruss_uart [] (unwind_backtrace+0x0/0xec) from [] (warn_slowpath_common+0x4c/0x64) [] (warn_slowpath_common+0x4c/0x64) from [] (warn_slowpath_null+0x18/0x1c) [] (warn_slowpath_null+0x18/0x1c) from [] (uart_carrier_raised+0x2c/0x74) [] (uart_carrier_raised+0x2c/0x74) from [] (tty_port_carrier_raised+0x1c/0x20) [] (tty_port_carrier_raised+0x1c/0x20) from [] (tty_port_block_til_ready+0x254/0x328) [] (tty_port_block_til_ready+0x254/0x328) from [] (tty_open+0x310/0x478) [] (tty_open+0x310/0x478) from [] (chrdev_open+0x1b4/0x1d0) [] (chrdev_open+0x1b4/0x1d0) from [] (__dentry_open+0x170/0x27c) [] (__dentry_open+0x170/0x27c) from [] (nameidata_to_filp+0x50/0x5c) [] (nameidata_to_filp+0x50/0x5c) from [] (finish_open+0x90/0x17c) [] (finish_open+0x90/0x17c) from [] (do_filp_open+0x23c/0x520) [] (do_filp_open+0x23c/0x520) from [] (do_sys_open+0x58/0xe4) [] (do_sys_open+0x58/0xe4) from [] (ret_fast_syscall+0x0/0x2c) flags ---> 0xA0000013 This is how I generated the trace: static void pruss_suart_enable_ms(struct uart_port *port) { struct omapl_pru_suart *soft_uart = container_of(port, struct omapl_pru_suart, port[port->line]); struct device *dev = soft_uart->dev; WARN_ON(1); dev_dbg(dev, "modem control timer not supported\n"); } -- 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/