From 368e21aebe9535c1643b272aaa9819298a6bc3e5 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Wed, 19 Oct 2016 21:02:04 +0300 Subject: [PATCH] rtc: cmos: Don't enable interrupts in the middle of the interrupt handler MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Using spin_lock_irq()/spin_unlock_irq() from within the interrupt handler is a no-no. Let's save/restore the flags to avoid turning on interrupts prematurely. We hit this in a bunch of our CI systems, but for whatever reason I wasn't able to reproduce on my own machine, so this fix is just based on the backtrace. [ 202.634918] WARNING: CPU: 0 PID: 0 at kernel/locking/lockdep.c:2729 trace_hardirqs_on_caller+0x113/0x1b0 [ 202.634919] DEBUG_LOCKS_WARN_ON(current->hardirq_context) [ 202.634929] Modules linked in: snd_hda_intel i915 x86_pkg_temp_thermal intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul ghash_clmulni_intel lpc_ich snd_hda_codec_realtek snd_hda_codec_generic snd_hda_codec_hdmi snd_hda_codec snd_hwdep i2c_designware_platform i2c_designware_core snd_hda_core mei_me mei snd_pcm r8169 mii sdhci_acpi sdhci mmc_core i2c_hid [last unloaded: i915] [ 202.634930] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G U 4.9.0-rc1-CI-CI_DRM_1734+ #1 [ 202.634931] Hardware name: GIGABYTE M4HM87P-00/M4HM87P-00, BIOS F6 12/10/2014 [ 202.634933] ffff88011ea03d68 ffffffff8142dce5 ffff88011ea03db8 0000000000000000 [ 202.634934] ffff88011ea03da8 ffffffff8107e496 00000aa900000002 ffffffff81e249a0 [ 202.634935] ffffffff81815637 ffffffff82e7c280 0000000000000000 0000000000000004 [ 202.634936] Call Trace: [ 202.634939] [ 202.634939] [] dump_stack+0x67/0x92 [ 202.634941] [] __warn+0xc6/0xe0 [ 202.634944] [] ? _raw_spin_unlock_irq+0x27/0x50 [ 202.634945] [] warn_slowpath_fmt+0x4a/0x50 [ 202.634946] [] trace_hardirqs_on_caller+0x113/0x1b0 [ 202.634948] [] trace_hardirqs_on+0xd/0x10 [ 202.634949] [] _raw_spin_unlock_irq+0x27/0x50 [ 202.634951] [] rtc_handler+0x32/0xa0 [ 202.634954] [] acpi_ev_fixed_event_detect+0xd4/0xfb [ 202.634956] [] acpi_ev_sci_xrupt_handler+0xf/0x2d [ 202.634957] [] acpi_irq+0x11/0x2c [ 202.634960] [] __handle_irq_event_percpu+0x58/0x370 [ 202.634961] [] handle_irq_event_percpu+0x1e/0x50 [ 202.634962] [] handle_irq_event+0x34/0x60 [ 202.634963] [] handle_fasteoi_irq+0xa6/0x170 [ 202.634966] [] handle_irq+0x15/0x20 [ 202.634967] [] do_IRQ+0x68/0x130 [ 202.634968] [] common_interrupt+0x89/0x89 [ 202.634970] [ 202.634970] [] ? mwait_idle+0x93/0x210 [ 202.634971] [] ? mwait_idle+0x8a/0x210 [ 202.634972] [] arch_cpu_idle+0xa/0x10 [ 202.634973] [] default_idle_call+0x1e/0x30 [ 202.634974] [] cpu_startup_entry+0x17c/0x1f0 [ 202.634976] [] rest_init+0x127/0x130 [ 202.634978] [] start_kernel+0x3f6/0x403 [ 202.634980] [] x86_64_start_reservations+0x2a/0x2c [ 202.634981] [] x86_64_start_kernel+0x173/0x186 [ 202.634982] ---[ end trace 293c99618fa08d34 ]--- Cc: Gabriele Mazzotta Cc: Alexandre Belloni Fixes: 983bf1256edb ("rtc: cmos: Clear ACPI-driven alarms upon resume") Signed-off-by: Ville Syrjälä Reviewed-by: Chris Wilson Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-cmos.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c index 6f0e12e66296..7030d7cd3861 100644 --- a/drivers/rtc/rtc-cmos.c +++ b/drivers/rtc/rtc-cmos.c @@ -996,8 +996,9 @@ static u32 rtc_handler(void *context) struct cmos_rtc *cmos = dev_get_drvdata(dev); unsigned char rtc_control = 0; unsigned char rtc_intr; + unsigned long flags; - spin_lock_irq(&rtc_lock); + spin_lock_irqsave(&rtc_lock, flags); if (cmos_rtc.suspend_ctrl) rtc_control = CMOS_READ(RTC_CONTROL); if (rtc_control & RTC_AIE) { @@ -1006,7 +1007,7 @@ static u32 rtc_handler(void *context) rtc_intr = CMOS_READ(RTC_INTR_FLAGS); rtc_update_irq(cmos->rtc, 1, rtc_intr); } - spin_unlock_irq(&rtc_lock); + spin_unlock_irqrestore(&rtc_lock, flags); pm_wakeup_event(dev, 0); acpi_clear_event(ACPI_EVENT_RTC); -- 2.20.1