Patch "pinctrl: baytrail: Fix lockdep" has been added to the 4.8-stable tree

This is a note to let you know that I've just added the patch titled

pinctrl: baytrail: Fix lockdep

to the 4.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
pinctrl-baytrail-fix-lockdep.patch
and it can be found in the queue-4.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <[email protected]>
Date: Mon, 3 Oct 2016 17:56:55 +0300
Subject: pinctrl: baytrail: Fix lockdep
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From: Ville Syrjälä <[email protected]>

commit a171bc51fa697021e1b2082d7e95c12a363bc0a9 upstream.

Initialize the spinlock before using it.

INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.

CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.8.0-dwc-bisect #4
Hardware name: Intel Corp. VALLEYVIEW C0 PLATFORM/BYT-T FFD8, BIOS BLAKFF81.X64.0088.R10.1403240443 FFD8_X64_R_2014_13_1_00 03/24/2014
 0000000000000000 ffff8800788ff770 ffffffff8133d597 0000000000000000
 0000000000000000 ffff8800788ff7e0 ffffffff810cfb9e 0000000000000002
 ffff8800788ff7d0 ffffffff8205b600 0000000000000002 ffff8800788ff7f0
Call Trace:
 [<ffffffff8133d597>] dump_stack+0x67/0x90
 [<ffffffff810cfb9e>] register_lock_class+0x52e/0x540
 [<ffffffff810d2081>] __lock_acquire+0x81/0x16b0
 [<ffffffff810cede1>] ? save_trace+0x41/0xd0
 [<ffffffff810d33b2>] ? __lock_acquire+0x13b2/0x16b0
 [<ffffffff810cf05a>] ? __lock_is_held+0x4a/0x70
 [<ffffffff810d3b1a>] lock_acquire+0xba/0x220
 [<ffffffff8136f1fe>] ? byt_gpio_get_direction+0x3e/0x80
 [<ffffffff81631567>] _raw_spin_lock_irqsave+0x47/0x60
 [<ffffffff8136f1fe>] ? byt_gpio_get_direction+0x3e/0x80
 [<ffffffff8136f1fe>] byt_gpio_get_direction+0x3e/0x80
 [<ffffffff813740a9>] gpiochip_add_data+0x319/0x7d0
 [<ffffffff81631723>] ? _raw_spin_unlock_irqrestore+0x43/0x70
 [<ffffffff8136fe3b>] byt_pinctrl_probe+0x2fb/0x620
 [<ffffffff8142fb0c>] platform_drv_probe+0x3c/0xa0

...

Based on the diff it looks like the problem was introduced in commit 71e6ca61e826 ("pinctrl: baytrail: Register pin control handling") but I wasn't able to verify that empirically as the parent commit just oopsed when I tried to boot it.

---
 drivers/pinctrl/intel/pinctrl-baytrail.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -1808,6 +1808,8 @@ static int byt_pinctrl_probe(struct plat
 		return PTR_ERR(vg->pctl_dev);
 	}
 
+	raw_spin_lock_init(&vg->lock);
+
 	ret = byt_gpio_probe(vg);
 	if (ret) {
 		pinctrl_unregister(vg->pctl_dev);

@@ -1815,7 +1817,6 @@ static int byt_pinctrl_probe(struct plat
 	}
 
 	platform_set_drvdata(pdev, vg);
-	raw_spin_lock_init(&vg->lock);
 	pm_runtime_enable(&pdev->dev);
 
 	return 0;

Patches currently in stable-queue which might be from [email protected] are

queue-4.8/x86-boot-smp-don-t-try-to-poke-disabled-non-existent-apic.patch queue-4.8/pinctrl-baytrail-fix-lockdep.patch