openwrt/target/linux/ipq806x/patches/0026-pinctrl-msm-Silence-recursive-lockdep-warning.patch
John Crispin 3c1f6e358d ipq806x: Add support for IPQ806x chip family
Patches are generated using the "format-patch" command from the
following location:
*https://www.codeaurora.org/cgit/quic/kernel/galak-msm/log/?h=apq_ipq_base
*rev=0771849495b4128cac2faf7d49c85c729fc48b20
Patches numbered 76/77/102/103 have already been integrated in 3.14.12,
so they're not in this list.

All these patches are either integrated are pending integration into
kernel.org, therefore these patches should go away once the kernel
gets upgraded to 3.16.

Support is currently limited to AP148 board but can be extended to other
platforms in the future.

These changes do not cover ethernet connectivity.

Signed-off-by: Mathieu Olivari <mathieu@codeaurora.org>

SVN-Revision: 42334
2014-08-30 09:32:58 +00:00

74 lines
2.5 KiB
Diff

From 9588c91936434166007c3a15ad7f4e2f3729c5e7 Mon Sep 17 00:00:00 2001
From: Stephen Boyd <sboyd@codeaurora.org>
Date: Thu, 6 Mar 2014 22:44:40 -0800
Subject: [PATCH 026/182] pinctrl: msm: Silence recursive lockdep warning
If a driver calls enable_irq_wake() on a gpio turned interrupt
from the msm pinctrl driver we'll get a lockdep warning like so:
=============================================
[ INFO: possible recursive locking detected ]
3.14.0-rc3 #2 Not tainted
---------------------------------------------
modprobe/52 is trying to acquire lock:
(&irq_desc_lock_class){-.....}, at: [<c026aea0>] __irq_get_desc_lock+0x48/0x88
but task is already holding lock:
(&irq_desc_lock_class){-.....}, at: [<c026aea0>] __irq_get_desc_lock+0x48/0x88
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&irq_desc_lock_class);
lock(&irq_desc_lock_class);
*** DEADLOCK ***
May be due to missing lock nesting notation
4 locks held by modprobe/52:
#0: (&__lockdep_no_validate__){......}, at: [<c04f2864>] __driver_attach+0x48/0x98
#1: (&__lockdep_no_validate__){......}, at: [<c04f2874>] __driver_attach+0x58/0x98
#2: (&irq_desc_lock_class){-.....}, at: [<c026aea0>] __irq_get_desc_lock+0x48/0x88
#3: (&(&pctrl->lock)->rlock){......}, at: [<c04bb4b8>] msm_gpio_irq_set_wake+0x20/0xa8
Silence it by putting the gpios into their own lock class.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
drivers/pinctrl/pinctrl-msm.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/pinctrl/pinctrl-msm.c b/drivers/pinctrl/pinctrl-msm.c
index 0e43fdd..e61b30a 100644
--- a/drivers/pinctrl/pinctrl-msm.c
+++ b/drivers/pinctrl/pinctrl-msm.c
@@ -857,6 +857,12 @@ static void msm_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
chained_irq_exit(chip, desc);
}
+/*
+ * This lock class tells lockdep that GPIO irqs are in a different
+ * category than their parents, so it won't report false recursion.
+ */
+static struct lock_class_key gpio_lock_class;
+
static int msm_gpio_init(struct msm_pinctrl *pctrl)
{
struct gpio_chip *chip;
@@ -895,6 +901,7 @@ static int msm_gpio_init(struct msm_pinctrl *pctrl)
for (i = 0; i < chip->ngpio; i++) {
irq = irq_create_mapping(pctrl->domain, i);
+ irq_set_lockdep_class(irq, &gpio_lock_class);
irq_set_chip_and_handler(irq, &msm_gpio_irq_chip, handle_edge_irq);
irq_set_chip_data(irq, pctrl);
}
--
1.7.10.4