netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Karsten Keil <isdn@linux-pingi.de>
Cc: Arnd Bergmann <arnd@arndb.de>,
	"David S. Miller" <davem@davemloft.net>,
	netdev@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [patch] mISDN: fix a loop count
Date: Tue, 15 Dec 2015 13:07:52 +0300	[thread overview]
Message-ID: <20151215100752.GC20848@mwanda> (raw)

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 <dan.carpenter@oracle.com>

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 */

             reply	other threads:[~2015-12-15 10:08 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-15 10:07 Dan Carpenter [this message]
2015-12-15 17:51 ` [patch] mISDN: fix a loop count David Miller

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20151215100752.GC20848@mwanda \
    --to=dan.carpenter@oracle.com \
    --cc=arnd@arndb.de \
    --cc=davem@davemloft.net \
    --cc=isdn@linux-pingi.de \
    --cc=kernel-janitors@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).