Re: About the fixes of /drivers/serial/8250.C in 2.6.17-rc6 for avoiding habbg-up

[Alan Cox <alan@lxorguk.ukuu.org.uk>]

Ar Llu, 2006-06-19 am 12:03 +0900, ysgrifennodd gouji:
> In /drivers/serial/8250.C of 2.6.17-rc6,
> 
> these fixes are adapted for avoinding  the problem of hang-up
> while TTY write and console write from kernel conflicted.

Yes, there is a bug in this version that was not in the one I submitted,
someone added an improvement.

> +   if (oops_in_progress) {
> +      locked = spin_trylock_irqsave(&up->port.lock, flags);
> +   } else
> +      spin_lock_irqsave(&up->port.lock, flags);
> +

It could always use spin_trylock_irqsave(). The oops in progress
optimisation makes some sense initially but there are many console
printk users that can occur during serial I/O in exceptional cases.

It's not an easy problem to solve with the current serial locking.

Alan

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