linux-kernel - [PATCH V2 RESEND] tty/n_gsm.c: use gsm->num to remove mux itself from gsm

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Message-Id: <57874F5F.5050000@linux.vnet.ibm.com>
Date:	Thu, 14 Jul 2016 16:37:51 +0800
From:	xinhui <xinhui.pan@...ux.vnet.ibm.com>
To:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
CC:	Jiri Slaby <jslaby@...e.com>, yanmin_zhang@...ux.intel.com,
	alan@...ux.intel.com, gregkh@...uxfoundation.org
Subject: [PATCH V2 RESEND] tty/n_gsm.c: use gsm->num to remove mux itself
 from gsm_mux[]

From: Pan Xinhui <xinhui.pan@...ux.vnet.ibm.com>

There is one filed gsm->num to store mux's index of gsm_mux[]. So use
gsm->num to remove itself from gsm_mux[] instead of the for-loop
traverse in gsm_cleanup_mux().

Signed-off-by: Pan Xinhui <xinhui.pan@...ux.vnet.ibm.com>
Reviewed-by: Alan Cox <alan@...ux.intel.com>
---
change from V1:
	lock is also held for the if()
---
  drivers/tty/n_gsm.c | 13 +++++--------
  1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 9aff371..697b31e 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2038,16 +2038,13 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm)
  	gsm->dead = 1;
  
  	spin_lock(&gsm_mux_lock);
-	for (i = 0; i < MAX_MUX; i++) {
-		if (gsm_mux[i] == gsm) {
-			gsm_mux[i] = NULL;
-			break;
-		}
-	}
-	spin_unlock(&gsm_mux_lock);
  	/* open failed before registering => nothing to do */
-	if (i == MAX_MUX)
+	if (gsm_mux[gsm->num] != gsm) {
+		spin_unlock(&gsm_mux_lock);
  		return;
+	}
+	gsm_mux[gsm->num] = NULL;
+	spin_unlock(&gsm_mux_lock);
  
  	/* In theory disconnecting DLCI 0 is sufficient but for some
  	   modems this is apparently not the case. */
-- 
1.9.1