Re: [PATCH] thermal: Don't call thermal_zone_device_update inside spinlock

From: Srinivas Pandruvada
Date: Tue Nov 25 2014 - 12:57:17 EST


On Tue, 2014-11-25 at 01:23 -0400, Eduardo Valentin wrote:
Hi,
> Hi,
>
> A minor thing. Your patch title makes us think this fix affects the
> thermal subsystem completely, whereas it affects a specific driver.
>
Good point. I overlooked this.

Maurice,
Change the title to something like
"thermal: Intel SoC DTS: Don't call thermal_zone_device_update inside
spinlock"

Thanks,
Srinivas
>
> On Thu, Nov 13, 2014 at 06:47:04PM +0800, Maurice Petallo wrote:
> > The driver calls spin_lock_irqsave during DTS interrupt. The interrupt
> > handle then calls thermal_zone_device_update which implicitly calls
> > a sleep function and produce the following bug:
> >
>
> > BUG: sleeping function called from invalid context at kernel/locking/mutex.c:97
> > in_atomic(): 1, irqs_disabled(): 1, pid: 920, name: irq/86-soc_dts
> > CPU: 0 PID: 920 Comm: irq/86-soc_dts Tainted: G E 3.17.0-rc2+ #1
> > Hardware name: Intel Corp. VALLEYVIEW B3 PLATFORM/NOTEBOOK, BIOS BYTICRB1.86C.0092.R31.1408290850 08/29/2014
> > 00000000 00000000 c25dbe74 c1818cfd f3cc488c c25dbe9c c1059305 c1b4063b
> > 00000001 00000001 00000398 f3cc488c f6817644 f6817644 f3ecc6c0 c25dbea8
> > c18208f2 f6817400 c25dbebc c159b0bb c25dbedc f6817400 f32a2300 c25dbee8
> > Call Trace:
> > [<c1818cfd>] dump_stack+0x48/0x60
> > [<c1059305>] __might_sleep+0xec/0xf4
> > [<c18208f2>] mutex_lock+0x1c/0x34
> > [<c159b0bb>] thermal_zone_get_temp+0x34/0x59
> > [<c159bde5>] thermal_zone_device_update+0x2d/0xcb
> > [<f85da16a>] ? iosf_mbi_write+0x6c/0x74 [iosf_mbi]
> > [<f7c7445d>] soc_irq_thread_fn+0x10c/0x163 [intel_soc_dts_thermal]
> > [<c107b72b>] irq_thread_fn+0x18/0x2a
> > [<c107bedb>] irq_thread+0x81/0x11f
> > [<c107b713>] ? irq_finalize_oneshot+0x7c/0x7c
> > [<c107bf79>] ? irq_thread+0x11f/0x11f
> > [<c107be5a>] ? wake_threads_waitq+0x31/0x31
> > [<c1054217>] kthread+0x87/0x8c
> > [<c1821e41>] ret_from_kernel_thread+0x21/0x30
> > [<c1054190>] ? __kthread_parkme+0x55/0x55
> >
> > Signed-off-by: Maurice Petallo <mauricex.r.petallo@xxxxxxxxx>
> > Acked-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
> > ---
> > drivers/thermal/intel_soc_dts_thermal.c | 12 +++++++-----
> > 1 file changed, 7 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/thermal/intel_soc_dts_thermal.c b/drivers/thermal/intel_soc_dts_thermal.c
> > index a6a0a18..5580f5b 100644
> > --- a/drivers/thermal/intel_soc_dts_thermal.c
> > +++ b/drivers/thermal/intel_soc_dts_thermal.c
> > @@ -360,6 +360,9 @@ static void proc_thermal_interrupt(void)
> > u32 sticky_out;
> > int status;
> > u32 ptmc_out;
> > + unsigned long flags;
> > +
> > + spin_lock_irqsave(&intr_notify_lock, flags);
> >
> > /* Clear APIC interrupt */
> > status = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ,
> > @@ -378,21 +381,20 @@ static void proc_thermal_interrupt(void)
> > /* reset sticky bit */
> > status = iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE,
> > SOC_DTS_OFFSET_PTTSS, sticky_out);
> > + spin_unlock_irqrestore(&intr_notify_lock, flags);
> > +
> > for (i = 0; i < SOC_MAX_DTS_SENSORS; ++i) {
> > pr_debug("TZD update for zone %d\n", i);
> > thermal_zone_device_update(soc_dts[i]->tzone);
> > }
> > - }
> > + } else
> > + spin_unlock_irqrestore(&intr_notify_lock, flags);
> >
> > }
> >
> > static irqreturn_t soc_irq_thread_fn(int irq, void *dev_data)
> > {
> > - unsigned long flags;
> > -
> > - spin_lock_irqsave(&intr_notify_lock, flags);
> > proc_thermal_interrupt();
> > - spin_unlock_irqrestore(&intr_notify_lock, flags);
> > pr_debug("proc_thermal_interrupt\n");
> >
> > return IRQ_HANDLED;
>
> A part from the minor thing I mentioned before, you can add my:
>
> Acked-by: Eduardo Valentin <edubezval@xxxxxxxxx>
>
> > --
> > 1.7.9.5
> >
> > --
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