From 40d24c4d8a7430aa4dfd7a665fa3faf3b05b673f Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 15 Dec 2015 13:07:52 +0300 Subject: [PATCH] mISDN: fix a loop count 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 --- 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 a77eea5..cb428b9 100644 --- a/drivers/isdn/hardware/mISDN/mISDNipac.c +++ b/drivers/isdn/hardware/mISDN/mISDNipac.c @@ -1170,7 +1170,7 @@ 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); @@ -1182,7 +1182,7 @@ 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); @@ -1200,7 +1200,7 @@ 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) @@ -1211,7 +1211,6 @@ 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 */ -- 2.7.4