68 lines
2.4 KiB
Diff
68 lines
2.4 KiB
Diff
From 1b2bdd19742d4a336a4865d9b352c7a0ca7028ee Mon Sep 17 00:00:00 2001
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From: Gabor Juhos <juhosg@openwrt.org>
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Date: Wed, 25 Sep 2013 10:00:10 +0200
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Subject: [PATCH] avr32: balance cpu_idle_poll_ctrl calls
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Since commit 01426478df3a8791ff5c8b6b82d409e699cfaf38
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(avr32: Use generic idle loop) the kernel throws the
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following warning on avr32:
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WARNING: at 900322e4 [verbose debug info unavailable]
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Modules linked in:
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CPU: 0 PID: 0 Comm: swapper Not tainted 3.12.0-rc2 #117
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task: 901c3ecc ti: 901c0000 task.ti: 901c0000
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PC is at cpu_idle_poll_ctrl+0x1c/0x38
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LR is at comparator_mode+0x3e/0x40
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pc : [<900322e4>] lr : [<90014882>] Not tainted
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sp : 901c1f74 r12: 00000000 r11: 901c74a0
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r10: 901d2510 r9 : 00000001 r8 : 901db4de
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r7 : 901c74a0 r6 : 00000001 r5 : 00410020 r4 : 901db574
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r3 : 00410024 r2 : 90206fe0 r1 : 00000000 r0 : 007f0000
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Flags: qvnzc
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Mode bits: hjmde....G
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CPU Mode: Supervisor
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Call trace:
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[<90039ede>] clockevents_set_mode+0x16/0x2e
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[<90039f00>] clockevents_shutdown+0xa/0x1e
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[<9003a078>] clockevents_exchange_device+0x58/0x70
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[<9003a78c>] tick_check_new_device+0x38/0x54
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[<9003a1a2>] clockevents_register_device+0x32/0x90
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[<900035c4>] time_init+0xa8/0x108
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[<90000520>] start_kernel+0x128/0x23c
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When the 'avr32_comparator' clockevent device is registered,
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the clockevent core sets the mode of that clockevent device
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to CLOCK_EVT_MODE_SHUTDOWN. Due to this, the 'comparator_mode'
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function calls the 'cpu_idle_poll_ctrl' to disables idle poll.
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This results in the aforementioned warning because the polling
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is not enabled yet.
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Change the code to only disable idle poll if it is enabled by
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the same function to avoid the warning.
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Cc: stable@vger.kernel.org
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Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
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---
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Note: the patch is against v3.12-rc2.
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---
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arch/avr32/kernel/time.c | 9 ++++++++-
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1 file changed, 8 insertions(+), 1 deletion(-)
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--- a/arch/avr32/kernel/time.c
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+++ b/arch/avr32/kernel/time.c
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@@ -98,7 +98,14 @@ static void comparator_mode(enum clock_e
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case CLOCK_EVT_MODE_SHUTDOWN:
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sysreg_write(COMPARE, 0);
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pr_debug("%s: stop\n", evdev->name);
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- cpu_idle_poll_ctrl(false);
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+ if (evdev->mode == CLOCK_EVT_MODE_ONESHOT ||
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+ evdev->mode == CLOCK_EVT_MODE_RESUME) {
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+ /*
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+ * Only disable idle poll if we have forced that
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+ * in a previous call.
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+ */
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+ cpu_idle_poll_ctrl(false);
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+ }
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break;
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default:
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BUG();
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