Anton Vorontsov 377bf1e4ac genirq: fix irq_desc->depth handling with DEBUG_SHIRQ ... When DEBUG_SHIRQ is selected, a spurious IRQ is issued before the setup_irq() initializes the desc->depth. An IRQ handler may call disable_irq_nosync(), but then setup_irq() will overwrite desc->depth, and upon enable_irq() we'll catch this WARN: ------------[ cut here ]------------ Badness at kernel/irq/manage.c:180 NIP: c0061ab8 LR: c0061f10 CTR: 00000000 REGS: cf83be50 TRAP: 0700 Not tainted (2.6.27-rc3-23450-g74919b0) MSR: 00021032 <ME,IR,DR> CR: 22042022 XER: 20000000 TASK = cf829100[5] 'events/0' THREAD: cf83a000 GPR00: c0061f10 cf83bf00 cf829100 c038e674 00000016 00000000 cf83bef8 00000038 GPR08: c0298910 00000000 c0310d28 cf83a000 00000c9c 1001a1a8 0fffe000 00800000 GPR16: ffffffff 00000000 007fff00 00000000 007ffeb0 c03320a0 c031095c c0310924 GPR24: cf8292ec cf807190 cf83a000 00009032 c038e6a4 c038e674 cf99b1cc c038e674 NIP [c0061ab8] __enable_irq+0x20/0x80 LR [c0061f10] enable_irq+0x50/0x70 Call Trace: [cf83bf00] [c038e674] irq_desc+0x630/0x9000 (unreliable) [cf83bf10] [c0061f10] enable_irq+0x50/0x70 [cf83bf30] [c01abe94] phy_change+0x68/0x108 [cf83bf50] [c0046394] run_workqueue+0xc4/0x16c [cf83bf90] [c0046834] worker_thread+0x74/0xd4 [cf83bfd0] [c004ab7c] kthread+0x48/0x84 [cf83bff0] [c00135e0] kernel_thread+0x44/0x60 Instruction dump: 4e800020 3d20c031 38a94214 4bffffcc 9421fff0 7c0802a6 93e1000c 7c7f1b78 90010014 8123001c 2f890000 409e001c <0fe00000> 80010014 83e1000c 38210010 That trace corresponds to this line: WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); The patch fixes the problem by moving the SHIRQ code below the setup_irq(). Unfortunately we can't easily move the SHIRQ code inside the setup_irq(), since it grabs a spinlock, so to prvent a 'real' IRQ from interfere us we should disable that IRQ. p.s. The driver in question is drivers/net/phy/phy.c. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>		2008-08-22 08:07:21 +02:00
..
autoprobe.c	[PATCH] genirq: add handle_bad_irq()	2006-06-29 10:26:24 -07:00
chip.c	cpumask: Cleanup more uses of CPU_MASK and NODE_MASK	2008-04-19 19:44:58 +02:00
devres.c	kernel: explicitly include required header files under kernel/	2008-04-29 08:06:04 -07:00
handle.c	genirq: remove last NO_IDLE_HZ leftovers	2008-07-22 08:39:57 +02:00
internals.h	[PATCH] genirq: more verbose debugging on unexpected IRQ vectors	2006-06-29 10:26:25 -07:00
Makefile	[PATCH] sort the devres mess out	2007-02-11 11:18:07 -08:00
manage.c	genirq: fix irq_desc->depth handling with DEBUG_SHIRQ	2008-08-22 08:07:21 +02:00
migration.c	[PATCH] genirq: Mask irqs when migrating them.	2007-02-26 10:34:08 -08:00
proc.c	genirq: Expose default irq affinity mask (take 3)	2008-06-05 15:18:30 +02:00
resend.c	genirq: suppress resend of level interrupts	2007-08-12 11:05:45 -07:00
spurious.c	genirq: enable polling for disabled screaming irqs	2008-07-18 19:21:13 +02:00