The spurious IRQ testing in request_irq is mishandled in
um_request_irq, which sets the incoming file descriptors non-blocking
only after request_irq succeeds. This results in the spurious irq
calling read on a blocking descriptor, and a hang.
Fixed by reversing the O_NONBLOCK setting and the request_irq call.
Signed-off-by: Jeff Dike <[email protected]>
---
arch/um/kernel/irq.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
Index: linux-2.6.22/arch/um/kernel/irq.c
===================================================================
--- linux-2.6.22.orig/arch/um/kernel/irq.c 2007-10-25 12:23:09.000000000 -0400
+++ linux-2.6.22/arch/um/kernel/irq.c 2007-10-29 13:00:18.000000000 -0400
@@ -347,14 +347,15 @@ int um_request_irq(unsigned int irq, int
{
int err;
- err = request_irq(irq, handler, irqflags, devname, dev_id);
- if (err)
- return err;
-
- if (fd != -1)
+ if (fd != -1) {
err = activate_fd(irq, fd, type, dev_id);
- return err;
+ if (err)
+ return err;
+ }
+
+ return request_irq(irq, handler, irqflags, devname, dev_id);
}
+
EXPORT_SYMBOL(um_request_irq);
EXPORT_SYMBOL(reactivate_fd);