Date: Fri, 24 Feb 2006 15:36:14 -0800 From: Maksim Yevmenkin <maksim.yevmenkin@savvis.net> To: freebsd-current@freebsd.org Subject: [PATCH] kbdmux(4) update Message-ID: <43FF986E.9030205@savvis.net>
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dear Hackers,
i was finally able to trace hard lockup problem with kbdmux(4), ps/2
keyboard and ps/2 mouse under x11.
the problem was traced back to the following code in kbdmux(4)
==
/* read all chars from the keyboard */
while (KBDMUX_CHECK_CHAR(kbd)) {
c = KBDMUX_READ_CHAR(kbd, 0);
if (c == NOKEY)
continue;
if (c == ERRKEY)
continue; /* XXX ring bell */
if (!KBD_IS_BUSY(kbd))
continue; /* not open - discard the input */
putc(c, &state->ks_inq);
}
==
it turns out that atkbd(4) check_char() method may return "true" while
read_char() method returns NOKEY. kbdmux(4) was simply stuck in the dead
loop.
this is only happening when kbdmux(4), ps/2 keyboard and ps/2 mouse used
together, and, here is why: atkbd_check_char() calls kbdc_data_ready().
the later will return "true" if there are pending data in either kbd or
aux queue.
so, could someone with atkbd(4) and psm(4) knowledge verify this? also
there is similar code in genkbd_event(), i.e.
==
/* read all pending input */
while ((*kbdsw[kbd->kb_index]->check_char)(kbd)) {
c = (*kbdsw[kbd->kb_index]->read_char)(kbd, FALSE);
if (c == NOKEY)
continue;
==
the following patch should fix the problem with kbdmux(4). please give
it a try and let me know if it works for you.
==
--- kbdmux.c.orig Mon Oct 17 23:38:14 2005
+++ kbdmux.c Fri Feb 24 15:27:51 2006
@@ -250,7 +250,7 @@
while (KBDMUX_CHECK_CHAR(kbd)) {
c = KBDMUX_READ_CHAR(kbd, 0);
if (c == NOKEY)
- continue;
+ break;
if (c == ERRKEY)
continue; /* XXX ring bell */
if (!KBD_IS_BUSY(kbd))
==
while i'm here, could someone please review the following patch for
ukbd(4). this patch makes ukbd(4) to not delay break scancodes in "raw"
mode.
==
--- ukbd.c.orig Wed Mar 30 00:32:41 2005
+++ ukbd.c Thu Feb 23 17:18:37 2006
@@ -1145,9 +1145,7 @@
state = (ukbd_state_t *)kbd->kb_data;
if (!(state->ks_flags & COMPOSE) && (state->ks_composed_char > 0))
return TRUE;
- if (state->ks_inputs > 0)
- return TRUE;
- return FALSE;
+ return ukbd_check(kbd);
}
/* some useful control functions */
==
thanks,
max
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