Char: nozomi, remove useless tty_sem
tty_sem used to protect tty open count. This was removed in 33dd474a
but the lock remained in place.
So remove it completely as it protects nothing now.
Also this solves Mac's problem with inatomic operation called from
atomic context (ppp):
BUG: scheduling while atomic: firefox-bin/1992/0x10000800
Modules linked in: ...
Pid: 1992, comm: firefox-bin Not tainted 2.6.38 #1
Call Trace:
...
[] ? mutex_lock+0xe/0x21
[] ? ntty_write+0x5d/0x192 [nozomi]
[] ? __mod_timer.clone.30+0xbe/0xcc
[] ? check_preempt_curr+0x60/0x6d
[] ? __nf_ct_refresh_acct+0x75/0xbe
[] ? ppp_async_push+0xa9/0x3bd [ppp_async]
[] ? ppp_async_send+0x34/0x40 [ppp_async]
[] ? ppp_push+0x6c/0x4f9 [ppp_generic]
...
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: Mac <kmac@poczta.fm>
Tested-by: Gerald Pfeifer <gerald@pfeifer.com>
Reviewed-by: Jack Stone <jwjstone@fastmail.fm>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/tty/nozomi.c b/drivers/tty/nozomi.c
index c34d622..b1aecc7 100644
--- a/drivers/tty/nozomi.c
+++ b/drivers/tty/nozomi.c
@@ -364,8 +364,6 @@
u8 toggle_ul;
u16 token_dl;
- /* mutex to ensure one access patch to this port */
- struct mutex tty_sem;
wait_queue_head_t tty_wait;
struct async_icount tty_icount;
@@ -1474,7 +1472,6 @@
struct device *tty_dev;
struct port *port = &dc->port[i];
port->dc = dc;
- mutex_init(&port->tty_sem);
tty_port_init(&port->port);
port->port.ops = &noz_tty_port_ops;
tty_dev = tty_register_device(ntty_driver, dc->index_start + i,
@@ -1688,8 +1685,6 @@
if (!dc || !port)
return -ENODEV;
- mutex_lock(&port->tty_sem);
-
rval = kfifo_in(&port->fifo_ul, (unsigned char *)buffer, count);
/* notify card */
@@ -1714,7 +1709,6 @@
spin_unlock_irqrestore(&dc->spin_mutex, flags);
exit:
- mutex_unlock(&port->tty_sem);
return rval;
}
@@ -1733,11 +1727,9 @@
int room = 4096;
const struct nozomi *dc = get_dc_by_tty(tty);
- if (dc) {
- mutex_lock(&port->tty_sem);
+ if (dc)
room = kfifo_avail(&port->fifo_ul);
- mutex_unlock(&port->tty_sem);
- }
+
return room;
}