linux-kernel - Re: [Linux v4.10.0-rc1+] Still call-traces after suspend-resume (pm? i915? cpu/hotplug?)

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Message-ID: <CAJZ5v0gp_BwxR+B3wtoLRh2B_ojY7cd9E5shJ8zsBeGL_LtnGg@mail.gmail.com>
Date:   Fri, 30 Dec 2016 15:02:06 +0100
From:   "Rafael J. Wysocki" <rafael@...nel.org>
To:     sedat.dilek@...il.com
Cc:     "Rafael J. Wysocki" <rafael@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Daniel Vetter <daniel.vetter@...ll.ch>,
        Jani Nikula <jani.nikula@...el.com>,
        Pavel Machek <pavel@....cz>,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
        Chris Wilson <chris@...is-wilson.co.uk>,
        intel-gfx <intel-gfx@...ts.freedesktop.org>,
        LKML <linux-kernel@...r.kernel.org>,
        "the arch/x86 maintainers" <x86@...nel.org>,
        Linux PM <linux-pm@...r.kernel.org>,
        Mika Kuoppala <mika.kuoppala@...ux.intel.com>
Subject: Re: [Linux v4.10.0-rc1+] Still call-traces after suspend-resume (pm?
 i915? cpu/hotplug?)

On Fri, Dec 30, 2016 at 12:40 PM, Sedat Dilek <sedat.dilek@...il.com> wrote:
> Hi,
>
> I have already reported this issue in [1].
> One of the issue was solved.
> Unfortunately, it looks like there is still a different problem here
> (Ubuntu/precise AMD64).
>
> I tried v4.10-rc1 and latest Linus tree up to...
>
> commit 98473f9f3f9bd404873cd1178c8be7d6d619f0d1
> "mm/filemap: fix parameters to test_bit()"
>
> Here we go...
>
> [   29.636047] BUG: sleeping function called from invalid context at
> drivers/base/power/runtime.c:1032
> [   29.636055] in_atomic(): 1, irqs_disabled(): 0, pid: 1500, name: Xorg
> [   29.636058] 1 lock held by Xorg/1500:
> [   29.636060]  #0:  (&dev->struct_mutex){+.+.+.}, at:
> [<ffffffffa0680c13>] i915_mutex_lock_interruptible+0x43/0x140 [i915]
> [   29.636107] CPU: 0 PID: 1500 Comm: Xorg Not tainted
> 4.10.0-rc1-6-iniza-amd64 #1
> [   29.636109] Hardware name: SAMSUNG ELECTRONICS CO., LTD.
> 530U3BI/530U4BI/530U4BH/530U3BI/530U4BI/530U4BH, BIOS 13XK 03/28/2013
> [   29.636111] Call Trace:
> [   29.636120]  dump_stack+0x85/0xc2
> [   29.636124]  ___might_sleep+0x196/0x260
> [   29.636127]  __might_sleep+0x53/0xb0
> [   29.636131]  __pm_runtime_resume+0x7a/0x90
> [   29.636159]  intel_runtime_pm_get+0x25/0x90 [i915]
> [   29.636189]  aliasing_gtt_bind_vma+0xaa/0xf0 [i915]
> [   29.636220]  i915_vma_bind+0xaf/0x1e0 [i915]
> [   29.636248]  i915_gem_execbuffer_relocate_entry+0x513/0x6f0 [i915]
> [   29.636272]  i915_gem_execbuffer_relocate_vma.isra.34+0x188/0x250 [i915]
> [   29.636275]  ? trace_hardirqs_on+0xd/0x10
> [   29.636294]  ? i915_gem_execbuffer_reserve_vma.isra.31+0x152/0x1f0 [i915]
> [   29.636316]  ? i915_gem_execbuffer_reserve.isra.32+0x372/0x3a0 [i915]
> [   29.636342]  i915_gem_do_execbuffer.isra.38+0xa70/0x1a40 [i915]
> [   29.636347]  ? __might_fault+0x4e/0xb0
> [   29.636373]  i915_gem_execbuffer2+0xc5/0x260 [i915]
> [   29.636376]  ? __might_fault+0x4e/0xb0
> [   29.636395]  drm_ioctl+0x206/0x450 [drm]
> [   29.636420]  ? i915_gem_execbuffer+0x340/0x340 [i915]
> [   29.636425]  ? __fget+0x5/0x200
> [   29.636429]  do_vfs_ioctl+0x91/0x6f0
> [   29.636431]  ? __fget+0x111/0x200
> [   29.636433]  ? __fget+0x5/0x200
> [   29.636436]  SyS_ioctl+0x79/0x90
> [   29.636441]  entry_SYSCALL_64_fastpath+0x23/0xc6
>
> On suspend/resume I see the same call trace.
> [2] points to the "BUG" line.

Well, this appears to be an i915 issue, but not a serious one.

Clearly, a function that may sleep (pm_runtime_get_sync() in
intel_runtime_pm_get()) is called with disabled interrupts.  If I
understand the code correctly, though, it actually is not going to
sleep in this particular case, because pm_runtime_get_sync() has
already been called once for this device in the same code path which
means that this particular instance will return immediately, so this
is a false-positive (most likely).

Let me see if I the might_sleep_if() assertion in
__pm_runtime_resume(() can be moved to a better place.

Thanks,
Rafael