Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754996AbcJLMnn (ORCPT ); Wed, 12 Oct 2016 08:43:43 -0400 Received: from mail.kernel.org ([198.145.29.136]:46958 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753105AbcJLMmj (ORCPT ); Wed, 12 Oct 2016 08:42:39 -0400 From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Dan Carpenter , "David S. Miller" , Zefan Li Subject: [PATCH 3.4 087/125] mISDN: fix a loop count Date: Wed, 12 Oct 2016 20:33:23 +0800 Message-Id: <1476275641-4697-87-git-send-email-lizf@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1476275600-4626-1-git-send-email-lizf@kernel.org> References: <1476275600-4626-1-git-send-email-lizf@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2288 Lines: 65 From: Dan Carpenter 3.4.113-rc1 review patch. If anyone has any objections, please let me know. ------------------ 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: Zefan Li --- drivers/isdn/hardware/mISDN/mISDNipac.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/isdn/hardware/mISDN/mISDNipac.c b/drivers/isdn/hardware/mISDN/mISDNipac.c index 884369f..c0b787b 100644 --- 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 maxloop) 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 maxloop) } } 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 maxloop) 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 maxloop) mISDNisac_irq(isac, istad); if (0 == (ista | istad)) break; - cnt--; } } if (cnt > maxloop) /* only for ISAC/HSCX without PCI IRQ test */ -- 1.9.1