isdn: avoid calling tty_ldisc_flush() in atomic context

commit bc10f96757bd6ab3721510df8defa8f21c32f974 upstream.

Remove the call to tty_ldisc_flush() from the RESULT_NO_CARRIER
branch of isdn_tty_modem_result(), as already proposed in commit
00409bb045887ec5e7b9e351bc080c38ab6bfd33.
This avoids a "sleeping function called from invalid context" BUG
when the hardware driver calls the statcallb() callback with
command==ISDN_STAT_DHUP in atomic context, which in turn calls
isdn_tty_modem_result(RESULT_NO_CARRIER, ~), and from there,
tty_ldisc_flush() which may sleep.

Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/isdn/i4l/isdn_tty.c b/drivers/isdn/i4l/isdn_tty.c
index 2881a66c1aa97c2e78e0c9f3029bbbd44ef0046a..9f65c9cc4b9163e22db2a59cd5a3f4cf6357ffb4 100644 (file)
--- a/drivers/isdn/i4l/isdn_tty.c
+++ b/drivers/isdn/i4l/isdn_tty.c
@@ -2635,12 +2635,6 @@ isdn_tty_modem_result(int code, modem_info * info)
                if ((info->flags & ISDN_ASYNC_CLOSING) || (!info->tty)) {
                        return;
                }
-#ifdef CONFIG_ISDN_AUDIO
-               if ( !info->vonline )
-                       tty_ldisc_flush(info->tty);
-#else
-               tty_ldisc_flush(info->tty);
-#endif
                if ((info->flags & ISDN_ASYNC_CHECK_CD) &&
                    (!((info->flags & ISDN_ASYNC_CALLOUT_ACTIVE) &&
                       (info->flags & ISDN_ASYNC_CALLOUT_NOHUP)))) {