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authorGeert Uytterhoeven <geert+renesas@glider.be>2015-09-09 13:42:53 +0200
committerThomas Gleixner <tglx@linutronix.de>2015-09-15 17:06:29 +0200
commitb1370658804510f6a1c0517a8ff1c9534d371edd (patch)
tree5801c9e745b9640df1a9f01b8a4ac312e4b0e4be /drivers/irqchip
parent157add60cb35913b8a848a3d7e6456b8ed134796 (diff)
irqchip/renesas-irqc: Use a separate lockdep class
The renesas-irqc interrupt controller is cascaded to the GIC. Hence when propagating wake-up settings to its parent interrupt controller, the following lockdep warning is printed: ============================================= [ INFO: possible recursive locking detected ] 4.2.0-ape6evm-10725-g50fcd7643c034198 #280 Not tainted --------------------------------------------- s2ram/1072 is trying to acquire lock: (&irq_desc_lock_class){-.-...}, at: [<c008d3fc>] __irq_get_desc_lock+0x58/0x98 but task is already holding lock: (&irq_desc_lock_class){-.-...}, at: [<c008d3fc>] __irq_get_desc_lock+0x58/0x98 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 6 locks held by s2ram/1072: #0: (sb_writers#7){.+.+.+}, at: [<c012eb14>] __sb_start_write+0xa0/0xa8 #1: (&of->mutex){+.+.+.}, at: [<c019396c>] kernfs_fop_write+0x4c/0x1bc #2: (s_active#24){.+.+.+}, at: [<c0193974>] kernfs_fop_write+0x54/0x1bc #3: (pm_mutex){+.+.+.}, at: [<c008213c>] pm_suspend+0x10c/0x510 #4: (&dev->mutex){......}, at: [<c02af3c4>] __device_suspend+0xdc/0x2cc #5: (&irq_desc_lock_class){-.-...}, at: [<c008d3fc>] __irq_get_desc_lock+0x58/0x98 stack backtrace: CPU: 0 PID: 1072 Comm: s2ram Not tainted 4.2.0-ape6evm-10725-g50fcd7643c034198 #280 Hardware name: Generic R8A73A4 (Flattened Device Tree) [<c0018078>] (unwind_backtrace) from [<c00144f0>] (show_stack+0x10/0x14) [<c00144f0>] (show_stack) from [<c0451f14>] (dump_stack+0x88/0x98) [<c0451f14>] (dump_stack) from [<c007b29c>] (__lock_acquire+0x15cc/0x20e4) [<c007b29c>] (__lock_acquire) from [<c007c6e0>] (lock_acquire+0xac/0x12c) [<c007c6e0>] (lock_acquire) from [<c0457c00>] (_raw_spin_lock_irqsave+0x40/0x54) [<c0457c00>] (_raw_spin_lock_irqsave) from [<c008d3fc>] (__irq_get_desc_lock+0x58/0x98) [<c008d3fc>] (__irq_get_desc_lock) from [<c008ebbc>] (irq_set_irq_wake+0x20/0xf8) [<c008ebbc>] (irq_set_irq_wake) from [<c0260770>] (irqc_irq_set_wake+0x20/0x4c) [<c0260770>] (irqc_irq_set_wake) from [<c008ec28>] (irq_set_irq_wake+0x8c/0xf8) [<c008ec28>] (irq_set_irq_wake) from [<c02cb8c0>] (gpio_keys_suspend+0x74/0xc0) [<c02cb8c0>] (gpio_keys_suspend) from [<c02ae8cc>] (dpm_run_callback+0x54/0x124) Avoid this false positive by using a separate lockdep class for IRQC interrupts. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: Jason Cooper <jason@lakedaemon.net> Link: http://lkml.kernel.org/r/1441798974-25716-2-git-send-email-geert%2Brenesas@glider.be Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'drivers/irqchip')
-rw-r--r--drivers/irqchip/irq-renesas-irqc.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-renesas-irqc.c b/drivers/irqchip/irq-renesas-irqc.c
index 2aa3add711a6..4652cc385d39 100644
--- a/drivers/irqchip/irq-renesas-irqc.c
+++ b/drivers/irqchip/irq-renesas-irqc.c
@@ -150,6 +150,12 @@ static irqreturn_t irqc_irq_handler(int irq, void *dev_id)
return IRQ_NONE;
}
+/*
+ * This lock class tells lockdep that IRQC irqs are in a different
+ * category than their parents, so it won't report false recursion.
+ */
+static struct lock_class_key irqc_irq_lock_class;
+
static int irqc_irq_domain_map(struct irq_domain *h, unsigned int virq,
irq_hw_number_t hw)
{
@@ -157,6 +163,7 @@ static int irqc_irq_domain_map(struct irq_domain *h, unsigned int virq,
irqc_dbg(&p->irq[hw], "map");
irq_set_chip_data(virq, h->host_data);
+ irq_set_lockdep_class(virq, &irqc_irq_lock_class);
irq_set_chip_and_handler(virq, &p->irq_chip, handle_level_irq);
return 0;
}