From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johan Hovold Subject: USB-serial console and lockdep Date: Tue, 18 Nov 2014 17:18:33 +0100 Message-ID: <20141118161833.GA22786@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-wi0-f171.google.com ([209.85.212.171]:58930 "EHLO mail-wi0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932170AbaKRQ00 (ORCPT ); Tue, 18 Nov 2014 11:26:26 -0500 Content-Disposition: inline Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Peter Hurley Cc: linux-serial@vger.kernel.org, linux-usb@vger.kernel.org Hi Peter, I get this missing-lockdep-annotation warning which I haven't seen before when booting with a usb-serial console on 3.18-rc5. It's been a while since I last tested this, though, and the tty_ldisc_ref wasn't introduced until 833efc0ed19c ("USB: serial: invoke dcd_change ldisc's handler."). [ 10.575225] usbserial: USB Serial support registered for pl2303 [ 10.575561] pl2303 1-2.1:1.0: pl2303 converter detected [ 10.627563] usb 1-2.1: pl2303 converter now attached to ttyUSB0 [ 10.650939] INFO: trying to register non-static key. [ 10.651000] the code is fine but needs lockdep annotation. [ 10.651000] turning off the locking correctness validator. [ 10.651031] CPU: 0 PID: 68 Comm: udevd Tainted: G W 3.18.0-rc5 #10 [ 10.651092] [] (unwind_backtrace) from [] (show_stack+0x20/0x24) [ 10.651123] [] (show_stack) from [] (dump_stack+0x24/0x28) [ 10.651184] [] (dump_stack) from [] (__lock_acquire+0x1e50/0x2004) [ 10.651214] [] (__lock_acquire) from [] (lock_acquire+0xe4/0x18c) [ 10.651245] [] (lock_acquire) from [] (ldsem_down_read_trylock+0x78/0x90) [ 10.651275] [] (ldsem_down_read_trylock) from [] (tty_ldisc_ref+0x24/0x58) [ 10.651306] [] (tty_ldisc_ref) from [] (usb_serial_handle_dcd_change+0x48/0xe8) [ 10.651367] [] (usb_serial_handle_dcd_change) from [] (pl2303_read_int_callback+0x210/0x220 [pl2303]) [ 10.651428] [] (pl2303_read_int_callback [pl2303]) from [] (__usb_hcd_giveback_urb+0x80/0x140) [ 10.651458] [] (__usb_hcd_giveback_urb) from [] (usb_giveback_urb_bh+0x98/0xd4) [ 10.651489] [] (usb_giveback_urb_bh) from [] (tasklet_hi_action+0x9c/0x108) [ 10.651519] [] (tasklet_hi_action) from [] (__do_softirq+0x148/0x42c) [ 10.651550] [] (__do_softirq) from [] (irq_exit+0xd8/0x114) [ 10.651580] [] (irq_exit) from [] (__handle_domain_irq+0x84/0xdc) [ 10.651611] [] (__handle_domain_irq) from [] (omap_intc_handle_irq+0xd8/0xe0) [ 10.651641] [] (omap_intc_handle_irq) from [] (__irq_svc+0x44/0x7c) [ 10.651641] Exception stack(0xdf4e7f08 to 0xdf4e7f50) [ 10.651672] 7f00: debc0b80 df4e7f5c 00000000 00000000 debc0b80 be8da96c [ 10.651702] 7f20: 00000000 00000128 c000fc84 df4e6000 00000000 df4e7f94 00000004 df4e7f50 [ 10.651702] 7f40: c038ebc0 c038d74c 600f0013 ffffffff [ 10.651733] [] (__irq_svc) from [] (___sys_sendmsg.part.29+0x0/0x2e0) [ 10.651763] [] (___sys_sendmsg.part.29) from [] (SyS_sendmsg+0x18/0x1c) [ 10.651794] [] (SyS_sendmsg) from [] (ret_fast_syscall+0x0/0x48) [ 10.692871] console [ttyUSB0] enabled Johan