On Fri, Nov 27, 2015 at 12:09:30PM +0100, Petr Mladek wrote: > What we can do, though, is to zap all printk locks. We already do this > when a printk recursion is detected. This should be safe because > the system is crashing and there shouldn't be any printk caller > that would cause the deadlock. What about serial consoles which may call out to subsystems like the clk subsystem to enable a clock, which would want to take their own spinlocks in addition to the serial console driver? I don't see bust_spinlocks() dealing with any of these locks, so IMHO trying to make this work in NMI context strikes me as making the existing solution more unreliable on ARM systems. -- FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.
