On Tue, 23 Sep 2003, Thiemo Seufer wrote:
> > Can you please elaborate? tty is expected to be NULL if info->hook is
> > not, so the code after the change should not differ effectively -- only a
> > useless check is added at the end. Am I missing anything?
>
> AFAICS the
>
> while ((read_zsreg(info->zs_channel, R0) & Rx_CH_AV) != 0) {
>
> loops over the FIFO contents and 'return' discards the remaining
> part. The patch made a visible difference for me with some noisy
> debug printk()'s in the kernel.
Hmm, a coincidence? Without your patch the execution goes as follows:
receive_chars()
{
...
(*info->hook->rx_char)(ch, flag);
return;
}
And after the change it is as follows:
receive_chars()
{
...
(*info->hook->rx_char)(ch, flag);
if (tty)
tty_flip_buffer_push(tty);
return;
}
and tty is NULL. And I fail to see how it can it make any difference for
printk() output -- the code in question is only ever executed for input
from an LK201-type keyboard.
Maciej
--
+ Maciej W. Rozycki, Technical University of Gdansk, Poland +
+--------------------------------------------------------------+
+ e-mail: macro@ds2.pg.gda.pl, PGP key available +
