| From 1b0135b5e20c56b2edae29e92b91c0b12c983432 Mon Sep 17 00:00:00 2001 |
| From: Gabor Juhos <juhosg@openwrt.org> |
| Date: Wed, 25 Sep 2013 15:32:35 +0200 |
| Subject: avr32: fix clockevents kernel warning |
| |
| From: Gabor Juhos <juhosg@openwrt.org> |
| |
| commit 1b0135b5e20c56b2edae29e92b91c0b12c983432 upstream. |
| |
| 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. |
| |
| Signed-off-by: Gabor Juhos <juhosg@openwrt.org> |
| Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| arch/avr32/kernel/time.c | 9 ++++++++- |
| 1 file changed, 8 insertions(+), 1 deletion(-) |
| |
| --- a/arch/avr32/kernel/time.c |
| +++ b/arch/avr32/kernel/time.c |
| @@ -98,7 +98,14 @@ static void comparator_mode(enum clock_e |
| 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(); |