On Wed, Jan 23, 2008 at 02:55:59PM -0500, Joe Marcus Clarke wrote:
ng=20
boot=20
her=20
an=20
s:146
cture
not
tch ?
sp.
=20
=20
=46rom my reading of the code, scp would be non-NULL after the first open
of the corresponding /dev/ttyvX. sc_attach_unit() creates the scp for
the console and the consolectl devices.
VT_WAITACTIVE ioctl is performed on arbitrary syscons /dev node, and
can wait for any other screens, in particular, the screens that are
not opened at the moment (the reason for the reported panic).
The patch I posted may be improved by making the VT_WAITACTIVE ioctl
to wait for the scp being allocated, and only then for the screen to be
switched too. Please, test.
diff --git a/sys/dev/syscons/syscons.c b/sys/dev/syscons/syscons.c
index e0c9725..3127ae6 100644
--- a/sys/dev/syscons/syscons.c
+++ b/sys/dev/syscons/syscons.c
@@ -178,6 +178,7 @@ static int scparam(struct tty *tp, struct termios *t);
static void scstart(struct tty *tp);
static void scinit(int unit, int flags);
static scr_stat *sc_get_stat(struct cdev *devptr);
+static void sc_set_stat(struct cdev *devptr, scr_stat *st);
static void scterm(int unit, int flags);
static void scshutdown(void *arg, int howto);
static u_int scgetc(sc_softc_t *sc, u_int flags);
@@ -421,7 +422,7 @@ sc_attach_unit(int unit, int flags)
UID_ROOT, GID_WHEEL, 0600, "ttyv%r", vc + unit * MAXCONS);
sc_alloc_tty(sc->dev[vc]);
if (vc =3D=3D 0 && sc->dev =3D=3D main_devs)
- SC_STAT(sc->dev[0]) =3D &main_console;
+ sc_set_stat(sc->dev[0], &main_console);
}
/*
* The first vty already has struct tty and scr_stat initialized
@@ -434,7 +435,7 @@ sc_attach_unit(int unit, int flags)
UID_ROOT, GID_WHEEL, 0600, "consolectl");
sc_console_tty =3D sc_alloc_tty(dev);
ttyconsolemode(sc_console_tty, 0);
- SC_STAT(dev) =3D sc_console;
+ sc_set_stat(dev, sc_console);
=20
return 0;
}
@@ -525,7 +526,8 @@ scopen(struct cdev *dev, int flag, int mode, struct thr=
ead *td)
=20
scp =3D sc_get_stat(dev);
if (scp =3D=3D NULL) {
- scp =3D SC_STAT(dev) =3D alloc_scp(sc, SC_VTY(dev));
+ scp =3D alloc_scp(sc, SC_VTY(dev));
+ sc_set_stat(dev, scp);
if (ISGRAPHSC(scp))
sc_set_pixel_mode(scp, NULL, COL, ROW, 16, 8);
}
@@ -1063,6 +1065,7 @@ scioctl(struct cdev *dev, u_long cmd, caddr_t data, i=
nt flag, struct thread *td)
#endif
case VT_WAITACTIVE: /* wait for switch to occur */
i =3D (*(int *)data =3D=3D 0) ? scp->index : (*(int *)data - 1);
+ wait_active:
if ((i < sc->first_vty) || (i >=3D sc->first_vty + sc->vtys))
return EINVAL;
s =3D spltty();
@@ -1071,6 +1074,12 @@ scioctl(struct cdev *dev, u_long cmd, caddr_t data, =
int flag, struct thread *td)
if (error)
return error;
scp =3D sc_get_stat(SC_DEV(sc, i));
+ if (scp =3D=3D NULL) {
+ error =3D tsleep(&(dev)->si_drv1, PZERO | PCATCH, "waitvt0", 0);
+ if (error)
+ return (error);
+ goto wait_active;
+ }
if (scp =3D=3D scp->sc->cur_scp)
return 0;
error =3D tsleep(&scp->smode, PZERO | PCATCH, "waitvt", 0);
@@ -2769,7 +2778,7 @@ scinit(int unit, int flags)
UID_ROOT, GID_WHEEL, 0600, "ttyv%r", unit * MAXCONS);
sc_alloc_tty(sc->dev[0]);
scp =3D alloc_scp(sc, sc->first_vty);
- SC_STAT(sc->dev[0]) =3D scp;
+ sc_set_stat(sc->dev[0], scp);
}
sc->cur_scp =3D scp;
=20
@@ -3662,6 +3671,14 @@ sc_get_stat(struct cdev *devptr)
return (SC_STAT(devptr));
}
=20
+static void
+sc_set_stat(struct cdev *devptr, scr_stat *st)
+{
+
+ SC_STAT(devptr) =3D st;
+ wakeup(&devptr->si_drv1);
+}
+
/*
* Allocate active keyboard. Try to allocate "kbdmux" keyboard first, and,
* if found, add all non-busy keyboards to "kbdmux". Otherwise look for
