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); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/