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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>
This commit is contained in:
Jiri Slaby 2011-04-20 10:43:14 +02:00 committed by Greg Kroah-Hartman
parent 6d742f655e
commit 7fdc289311
1 changed files with 2 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
drivers/tty/nozomi.c
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@ -364,8 +364,6 @@ struct port {
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 @@ static int __devinit nozomi_card_init(struct pci_dev *pdev,
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 @@ static int ntty_write(struct tty_struct *tty, const unsigned char *buffer,
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 @@ static int ntty_write(struct tty_struct *tty, const unsigned char *buffer,
spin_unlock_irqrestore(&dc->spin_mutex, flags);
exit:
mutex_unlock(&port->tty_sem);
return rval;
}
@ -1733,11 +1727,9 @@ static int ntty_write_room(struct tty_struct *tty)
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;
}