[35/44] isdn: avoid calling tty_ldisc_flush() in atomic context

From: Greg KH
Date: Mon Mar 21 2011 - 19:14:12 EST

2.6.32-longterm review patch. If anyone has any objections, please let us know.


From: Tilman Schmidt <tilman@xxxxxxx>

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
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@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

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
@@ -2635,12 +2635,6 @@ isdn_tty_modem_result(int code, modem_in
if ((info->flags & ISDN_ASYNC_CLOSING) || (!info->tty)) {
- if ( !info->vonline )
- tty_ldisc_flush(info->tty);
- tty_ldisc_flush(info->tty);
if ((info->flags & ISDN_ASYNC_CHECK_CD) &&
(!((info->flags & ISDN_ASYNC_CALLOUT_ACTIVE) &&
(info->flags & ISDN_ASYNC_CALLOUT_NOHUP)))) {

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