From 47562277348da533f120acf2b0d4ff82a9444a1f Mon Sep 17 00:00:00 2001 From: Richard Weinberger Date: Mon, 9 Aug 2010 17:20:14 -0700 Subject: [PATCH] um: call free_irq() only on enabled channels When I use OpenSUSE-11.2 on UML (> 2.6.25) I get lots of such errors: Registering fd 1 twice Irqs : 3, 3 Ids : 0x09cb41a0, 0x09cb4120 ------------[ cut here ]------------ WARNING: at kernel/irq/manage.c:896 __free_irq+0x79/0x11a() Trying to free already-free IRQ 3 Modules linked in: 09dadc6c: [<081b2edb>] dump_stack+0x1c/0x20 09dadc84: [<080716da>] warn_slowpath_common+0x49/0x77 09dadc9c: [<08071772>] warn_slowpath_fmt+0x26/0x2a 09dadcb4: [<08094e08>] __free_irq+0x79/0x11a 09dadce4: [<08094ed6>] free_irq+0x2d/0x49 09dadcf4: [<0805b4bc>] close_one_chan+0x70/0x9c 09dadd0c: [<0805b833>] close_chan+0x17/0x22 09dadd1c: [<0805bdda>] enable_chan+0x70/0x7c 09dadd3c: [<0805cbb7>] line_open+0x34/0x9f 09dadd54: [<0805b21e>] con_open+0x13/0x35 09dadd6c: [<0814dc89>] tty_open+0x285/0x384 09dadda0: [<080b754e>] chrdev_open+0xe0/0xf9 09daddc0: [<080b3fb2>] __dentry_open+0xf3/0x1e2 09dadde4: [<080b4142>] nameidata_to_filp+0x35/0x49 09daddfc: [<080bd270>] do_last+0x409/0x50e 09dade28: [<080bea04>] do_filp_open+0x175/0x446 09dadecc: [<080b3d89>] do_sys_open+0x4a/0x128 09dadf04: [<080b3ea2>] sys_open+0x19/0x21 09dadf28: [<0805ab5a>] handle_syscall+0x7a/0x98 09dadf78: [<08068441>] userspace+0x2c9/0x370 09dadfe0: [<08058bb3>] fork_handler+0x53/0x5b 09dadffc: [<00766564>] 0x766564 ---[ end trace 9ebc1094aaf4bded ]--- This patch fixes the issue. Signed-off-by: Richard Weinberger Cc: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/drivers/chan_kern.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c index 6e51424745ab..25e1965df7ce 100644 --- a/arch/um/drivers/chan_kern.c +++ b/arch/um/drivers/chan_kern.c @@ -210,9 +210,9 @@ void free_irqs(void) list_for_each(ele, &list) { chan = list_entry(ele, struct chan, free_list); - if (chan->input) + if (chan->input && chan->enabled) free_irq(chan->line->driver->read_irq, chan); - if (chan->output) + if (chan->output && chan->enabled) free_irq(chan->line->driver->write_irq, chan); chan->enabled = 0; } @@ -231,9 +231,9 @@ static void close_one_chan(struct chan *chan, int delay_free_irq) spin_unlock_irqrestore(&irqs_to_free_lock, flags); } else { - if (chan->input) + if (chan->input && chan->enabled) free_irq(chan->line->driver->read_irq, chan); - if (chan->output) + if (chan->output && chan->enabled) free_irq(chan->line->driver->write_irq, chan); chan->enabled = 0; }