stallion: prune lock_kernel calls

Remove unneeded tty layer lock kernel bits. Relock the needed bits using the
port mutex. The istallion still has brd state races but those are not new
or introduced by the removal of the lock_kernel logic.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 13 insertions, 9 deletions

diff --git a/drivers/char/istallion.c b/drivers/char/istallion.c
index 4e395c956a09..750650cbac11 100644
--- a/drivers/char/istallion.c
+++ b/drivers/char/istallion.c
@@ -14,6 +14,7 @@
  *      the Free Software Foundation; either version 2 of the License, or
  *      (at your option) any later version.
  *
+ *      FIXME: brdp->state needs proper locking.
  */
 
 /*****************************************************************************/
@@ -4011,6 +4012,7 @@ static int stli_getbrdstats(combrd_t __user *bp)
                 return -ENODEV;
 
         memset(&stli_brdstats, 0, sizeof(combrd_t));
+
         stli_brdstats.brd = brdp->brdnr;
         stli_brdstats.type = brdp->brdtype;
         stli_brdstats.hwid = 0;
@@ -4076,10 +4078,13 @@ static int stli_portcmdstats(struct tty_struct *tty, struct stliport *portp)
         if (brdp == NULL)
                 return -ENODEV;
 
+        mutex_lock(&portp->port.mutex);
         if (brdp->state & BST_STARTED) {
                 if ((rc = stli_cmdwait(brdp, portp, A_GETSTATS,
-                    &stli_cdkstats, sizeof(asystats_t), 1)) < 0)
+                    &stli_cdkstats, sizeof(asystats_t), 1)) < 0) {
+                        mutex_unlock(&portp->port.mutex);
                         return rc;
+                }
         } else {
                 memset(&stli_cdkstats, 0, sizeof(asystats_t));
         }
@@ -4124,6 +4129,7 @@ static int stli_portcmdstats(struct tty_struct *tty, struct stliport *portp)
         stli_comstats.modem = stli_cdkstats.dcdcnt;
         stli_comstats.hwid = stli_cdkstats.hwid;
         stli_comstats.signals = stli_mktiocm(stli_cdkstats.signals);
+        mutex_unlock(&portp->port.mutex);
 
         return 0;
 }
@@ -4186,15 +4192,20 @@ static int stli_clrportstats(struct stliport *portp, comstats_t __user *cp)
         if (!brdp)
                 return -ENODEV;
 
+        mutex_lock(&portp->port.mutex);
+
         if (brdp->state & BST_STARTED) {
-                if ((rc = stli_cmdwait(brdp, portp, A_CLEARSTATS, NULL, 0, 0)) < 0)
+                if ((rc = stli_cmdwait(brdp, portp, A_CLEARSTATS, NULL, 0, 0)) < 0) {
+                        mutex_unlock(&portp->port.mutex);
                         return rc;
+                }
         }
 
         memset(&stli_comstats, 0, sizeof(comstats_t));
         stli_comstats.brd = portp->brdnr;
         stli_comstats.panel = portp->panelnr;
         stli_comstats.port = portp->portnr;
+        mutex_unlock(&portp->port.mutex);
 
         if (copy_to_user(cp, &stli_comstats, sizeof(comstats_t)))
                 return -EFAULT;
@@ -4266,8 +4277,6 @@ static long stli_memioctl(struct file *fp, unsigned int cmd, unsigned long arg)
         done = 0;
         rc = 0;
 
-        lock_kernel();
-
         switch (cmd) {
         case COM_GETPORTSTATS:
                 rc = stli_getportstats(NULL, NULL, argp);
@@ -4290,8 +4299,6 @@ static long stli_memioctl(struct file *fp, unsigned int cmd, unsigned long arg)
                 done++;
                 break;
         }
-        unlock_kernel();
-
         if (done)
                 return rc;
 
@@ -4308,8 +4315,6 @@ static long stli_memioctl(struct file *fp, unsigned int cmd, unsigned long arg)
         if (brdp->state == 0)
                 return -ENODEV;
 
-        lock_kernel();
-
         switch (cmd) {
         case STL_BINTR:
                 EBRDINTR(brdp);
@@ -4332,7 +4337,6 @@ static long stli_memioctl(struct file *fp, unsigned int cmd, unsigned long arg)
                 rc = -ENOIOCTLCMD;
                 break;
         }
-        unlock_kernel();
         return rc;
 }