From: Tilman Schmidt <tilman@imap.cc>
Date: Mon, 5 Jul 2010 14:18:27 +0000 (+0000)
Subject: isdn: avoid calling tty_ldisc_flush() in atomic context
X-Git-Tag: v2.6.27.59~77
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e8b2a4b819ccff589eb6d1dc274fc201a51cf7ed;p=thirdparty%2Fkernel%2Fstable.git

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 1a2222cbb8054..0d01a7147d900 100644
--- a/drivers/isdn/i4l/isdn_tty.c
+++ b/drivers/isdn/i4l/isdn_tty.c
@@ -2634,12 +2634,6 @@ 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)))) {