Re: [TTY] overrun notify issue during 5 minutes after booting

Re: [TTY] overrun notify issue during 5 minutes after booting

[moreau francis]

--- Andrew Morton <akpm@osdl.org> wrote:
> moreau francis <francis_moreau2000@yahoo.fr> wrote:
> 
> How does this look?
> 

It works well though I haven't tested the second
correction. But it looks good...
By the way, is it safe in "n_tty_receive_overrun" to
call
"printk" ? because the former can be called from IT
context...

    Francis 


	

	
		
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Re: [TTY] overrun notify issue during 5 minutes after booting

[Andrew Morton]

moreau francis <francis_moreau2000@yahoo.fr> wrote:
>
> By the way, is it safe in "n_tty_receive_overrun" to
>  call
>  "printk" ? because the former can be called from IT
>  context...

yup.  printk() is safe from all contexts except NMI.

[TTY] overrun notify issue during 5 minutes after booting

[moreau francis]

I noticed that TTY is not able to notify overrun issue
in "n_tty_receive_overrun". Actually it's because of
"time_before" macro which tests "tty->overrun_time" 
(equals to 0) against "jiffies - HZ" (something very
big
after booting).
I guess a simple way to solve it, is to initialize
"tty->overrun_time" to "jiffies". But it won't work if
an overrun appear after a very long while....

Thanks

    Francis


	

	
		
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Re: [TTY] overrun notify issue during 5 minutes after booting

[Andrew Morton]

moreau francis <francis_moreau2000@yahoo.fr> wrote:
>
> I noticed that TTY is not able to notify overrun issue
>  in "n_tty_receive_overrun". Actually it's because of
>  "time_before" macro which tests "tty->overrun_time" 
>  (equals to 0) against "jiffies - HZ" (something very
>  big
>  after booting).
>  I guess a simple way to solve it, is to initialize
>  "tty->overrun_time" to "jiffies". But it won't work if
>  an overrun appear after a very long while....

How does this look?


--- 25/drivers/char/tty_io.c~tty-overrun-time-fix	2005-03-14 01:45:43.000000000 -0800
+++ 25-akpm/drivers/char/tty_io.c	2005-03-14 01:46:02.000000000 -0800
@@ -2632,6 +2632,7 @@ static void initialize_tty_struct(struct
 	tty->magic = TTY_MAGIC;
 	tty_ldisc_assign(tty, tty_ldisc_get(N_TTY));
 	tty->pgrp = -1;
+	tty->overrun_time = jiffies;
 	tty->flip.char_buf_ptr = tty->flip.char_buf;
 	tty->flip.flag_buf_ptr = tty->flip.flag_buf;
 	INIT_WORK(&tty->flip.work, flush_to_ldisc, tty);
diff -puN drivers/char/n_tty.c~tty-overrun-time-fix drivers/char/n_tty.c
--- 25/drivers/char/n_tty.c~tty-overrun-time-fix	2005-03-14 01:49:25.000000000 -0800
+++ 25-akpm/drivers/char/n_tty.c	2005-03-14 01:50:10.000000000 -0800
@@ -606,9 +606,11 @@ static inline void n_tty_receive_overrun
 	char buf[64];
 
 	tty->num_overrun++;
-	if (time_before(tty->overrun_time, jiffies - HZ)) {
-		printk(KERN_WARNING "%s: %d input overrun(s)\n", tty_name(tty, buf),
-		       tty->num_overrun);
+	if (time_before(tty->overrun_time, jiffies - HZ) ||
+			time_after(tty->overrun_time, jiffies)) {
+		printk(KERN_WARNING "%s: %d input overrun(s)\n",
+			tty_name(tty, buf),
+			tty->num_overrun);
 		tty->overrun_time = jiffies;
 		tty->num_overrun = 0;
 	}
_