[81/82] isdn: avoid calling tty_ldisc_flush() in atomic context

[81/82] isdn: avoid calling tty_ldisc_flush() in atomic context

[Greg KH]

2.6.35-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Tilman Schmidt <tilman@imap.cc>

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>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 drivers/isdn/i4l/isdn_tty.c |    6 ------
 1 file changed, 6 deletions(-)

--- a/drivers/isdn/i4l/isdn_tty.c
+++ b/drivers/isdn/i4l/isdn_tty.c
@@ -2636,12 +2636,6 @@ isdn_tty_modem_result(int code, modem_in
 		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)))) {