Re: [PATCH] drivers/char/riscom8.c: save_flags()/cli()/sti()removal

[Amol Lad]

On Sat, 2006-10-14 at 15:20 +0100, Alan Cox wrote:
> Ar Gwe, 2006-10-13 am 17:10 +0530, ysgrifennodd Amol Lad:
> > Removed save_flags()/cli()/sti() and used (light weight) spin locks
> > 
> 
> Three things I see that look problematic

> 2. If the irq handler itself dumbly locks to fix this then we get
> tty_flip_buffer_push() re-entering the other code paths and deadlocking
> if low latency is enabled

The comment above tty_flip_buffer_push() says "This function must not be
called from IRQ context if tty->low_latency is set". In this case
tty_flip_buffer_push() is called from IRQ context. Do you think
tty->low_latency can still be set for this case ? or I misunderstood
your statement completely...

> 3. Some of the use of local_save/spin_lock_irq seems over-clever and
> unneeded

Let me know, I'll fix them too.

> 
> Fixable but how about we just delete the file since it has been broken
> for ages and nobody can be using it ?
> 

If we cannot delete the file then we must fix it. It's not good the
drivers using old and deprecated interfaces in current phase of kernel
development.

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