search for: uart_iir_no_int

I am seeing a problem with the Xen emulated serial console. When running a Linux 2.6.20 HVM guest that has CONFIG_HOTPLUG_CPU=n, the guest blocks on output to the console until it receives input keypresses from `xm console`. This prevents the guest from booting up without banging on some keys, and makes interactive use of the console difficult. By bisecting Linux kernel commits, I found that