diff options
Diffstat (limited to 'target/linux/ipq806x/patches/0026-pinctrl-msm-Silence-recursive-lockdep-warning.patch')
| -rw-r--r-- | target/linux/ipq806x/patches/0026-pinctrl-msm-Silence-recursive-lockdep-warning.patch | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/target/linux/ipq806x/patches/0026-pinctrl-msm-Silence-recursive-lockdep-warning.patch b/target/linux/ipq806x/patches/0026-pinctrl-msm-Silence-recursive-lockdep-warning.patch new file mode 100644 index 0000000000..fd2e10fb0f --- /dev/null +++ b/target/linux/ipq806x/patches/0026-pinctrl-msm-Silence-recursive-lockdep-warning.patch @@ -0,0 +1,73 @@ +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 + |