Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754879Ab3IYJb1 (ORCPT ); Wed, 25 Sep 2013 05:31:27 -0400 Received: from arrakis.dune.hu ([78.24.191.176]:47576 "EHLO arrakis.dune.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752230Ab3IYJbZ (ORCPT ); Wed, 25 Sep 2013 05:31:25 -0400 From: Gabor Juhos To: Hans-Christian Egtvedt Cc: Haavard Skinnemoen , Thomas Gleixner , linux-kernel@vger.kernel.org, Gabor Juhos , stable@vger.kernel.org Subject: [PATCH] avr32: balance cpu_idle_poll_ctrl calls Date: Wed, 25 Sep 2013 11:31:19 +0200 Message-Id: <1380101479-28358-1-git-send-email-juhosg@openwrt.org> X-Mailer: git-send-email 1.7.10 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2593 Lines: 72 Since commit 01426478df3a8791ff5c8b6b82d409e699cfaf38 (avr32: Use generic idle loop) the kernel throws the following warning on avr32: WARNING: at 900322e4 [verbose debug info unavailable] Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 3.12.0-rc2 #117 task: 901c3ecc ti: 901c0000 task.ti: 901c0000 PC is at cpu_idle_poll_ctrl+0x1c/0x38 LR is at comparator_mode+0x3e/0x40 pc : [<900322e4>] lr : [<90014882>] Not tainted sp : 901c1f74 r12: 00000000 r11: 901c74a0 r10: 901d2510 r9 : 00000001 r8 : 901db4de r7 : 901c74a0 r6 : 00000001 r5 : 00410020 r4 : 901db574 r3 : 00410024 r2 : 90206fe0 r1 : 00000000 r0 : 007f0000 Flags: qvnzc Mode bits: hjmde....G CPU Mode: Supervisor Call trace: [<90039ede>] clockevents_set_mode+0x16/0x2e [<90039f00>] clockevents_shutdown+0xa/0x1e [<9003a078>] clockevents_exchange_device+0x58/0x70 [<9003a78c>] tick_check_new_device+0x38/0x54 [<9003a1a2>] clockevents_register_device+0x32/0x90 [<900035c4>] time_init+0xa8/0x108 [<90000520>] start_kernel+0x128/0x23c When the 'avr32_comparator' clockevent device is registered, the clockevent core sets the mode of that clockevent device to CLOCK_EVT_MODE_SHUTDOWN. Due to this, the 'comparator_mode' function calls the 'cpu_idle_poll_ctrl' to disables idle poll. This results in the aforementioned warning because the polling is not enabled yet. Change the code to only disable idle poll if it is enabled by the same function to avoid the warning. Cc: stable@vger.kernel.org Signed-off-by: Gabor Juhos --- Note: the patch is against v3.12-rc2. --- arch/avr32/kernel/time.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/avr32/kernel/time.c b/arch/avr32/kernel/time.c index 869a1c6..12f828a 100644 --- a/arch/avr32/kernel/time.c +++ b/arch/avr32/kernel/time.c @@ -98,7 +98,14 @@ static void comparator_mode(enum clock_event_mode mode, case CLOCK_EVT_MODE_SHUTDOWN: sysreg_write(COMPARE, 0); pr_debug("%s: stop\n", evdev->name); - cpu_idle_poll_ctrl(false); + if (evdev->mode == CLOCK_EVT_MODE_ONESHOT || + evdev->mode == CLOCK_EVT_MODE_RESUME) { + /* + * Only disable idle poll if we have forced that + * in a previous call. + */ + cpu_idle_poll_ctrl(false); + } break; default: BUG(); -- 1.7.10 -- 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/