From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754194AbcARDiE (ORCPT ); Sun, 17 Jan 2016 22:38:04 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:59235 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752225AbcARDWD (ORCPT ); Sun, 17 Jan 2016 22:22:03 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Dan Carpenter" , "David S. Miller" Date: Mon, 18 Jan 2016 03:18:35 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 13/70] mISDN: fix a loop count In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.247 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.76-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter commit 40d24c4d8a7430aa4dfd7a665fa3faf3b05b673f upstream. There are two issue here. 1) cnt starts as maxloop + 1 so all these loops iterate one more time than intended. 2) At the end of the loop we test for "if (maxloop && !cnt)" but for the first two loops, we end with cnt equal to -1. Changing this to a pre-op means we end with cnt set to 0. Fixes: cae86d4a4e56 ('mISDN: Add driver for Infineon ISDN chipset family') Signed-off-by: Dan Carpenter Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- drivers/isdn/hardware/mISDN/mISDNipac.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- a/drivers/isdn/hardware/mISDN/mISDNipac.c +++ b/drivers/isdn/hardware/mISDN/mISDNipac.c @@ -1156,7 +1156,7 @@ mISDNipac_irq(struct ipac_hw *ipac, int if (ipac->type & IPAC_TYPE_IPACX) { ista = ReadIPAC(ipac, ISACX_ISTA); - while (ista && cnt--) { + while (ista && --cnt) { pr_debug("%s: ISTA %02x\n", ipac->name, ista); if (ista & IPACX__ICA) ipac_irq(&ipac->hscx[0], ista); @@ -1168,7 +1168,7 @@ mISDNipac_irq(struct ipac_hw *ipac, int } } else if (ipac->type & IPAC_TYPE_IPAC) { ista = ReadIPAC(ipac, IPAC_ISTA); - while (ista && cnt--) { + while (ista && --cnt) { pr_debug("%s: ISTA %02x\n", ipac->name, ista); if (ista & (IPAC__ICD | IPAC__EXD)) { istad = ReadISAC(isac, ISAC_ISTA); @@ -1186,7 +1186,7 @@ mISDNipac_irq(struct ipac_hw *ipac, int ista = ReadIPAC(ipac, IPAC_ISTA); } } else if (ipac->type & IPAC_TYPE_HSCX) { - while (cnt) { + while (--cnt) { ista = ReadIPAC(ipac, IPAC_ISTAB + ipac->hscx[1].off); pr_debug("%s: B2 ISTA %02x\n", ipac->name, ista); if (ista) @@ -1197,7 +1197,6 @@ mISDNipac_irq(struct ipac_hw *ipac, int mISDNisac_irq(isac, istad); if (0 == (ista | istad)) break; - cnt--; } } if (cnt > maxloop) /* only for ISAC/HSCX without PCI IRQ test */