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From: trix@redhat.com
To: jasmin@anw.at, mchehab@kernel.org, o.endriss@gmx.de, rjkm@metzlerbros.de
Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
	Tom Rix <trix@redhat.com>
Subject: [PATCH] media: dvb-frontends/cxd2099: report errors
Date: Wed, 22 Jul 2020 06:41:26 -0700	[thread overview]
Message-ID: <20200722134126.31191-1-trix@redhat.com> (raw)

From: Tom Rix <trix@redhat.com>

Clang static analysis reports this error

drivers/media/dvb-frontends/cxd2099.c:420:2: warning: Undefined
  or garbage value returned to caller
        return val;
        ^~~~~~~~~~

In read_cam_control, the call to read_io can fail.
When it fails val is not set.

The failure status should be returned to the caller,
not the unset val.

Similar problem with read_attribute_mem

Fixes: 0f0b270f905b ("[media] ngene: CXD2099AR Common Interface driver")

Signed-off-by: Tom Rix <trix@redhat.com>
---
 drivers/media/dvb-frontends/cxd2099.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/media/dvb-frontends/cxd2099.c b/drivers/media/dvb-frontends/cxd2099.c
index f88b5355493e..9dfaf18fc4b4 100644
--- a/drivers/media/dvb-frontends/cxd2099.c
+++ b/drivers/media/dvb-frontends/cxd2099.c
@@ -387,12 +387,15 @@ static int read_attribute_mem(struct dvb_ca_en50221 *ca,
 {
 	struct cxd *ci = ca->data;
 	u8 val;
+	int ret;
 
 	mutex_lock(&ci->lock);
 	set_mode(ci, 1);
-	read_pccard(ci, address, &val, 1);
+	ret = read_pccard(ci, address, &val, 1);
+	if (!ret)
+		ret = val;
 	mutex_unlock(&ci->lock);
-	return val;
+	return ret;
 }
 
 static int write_attribute_mem(struct dvb_ca_en50221 *ca, int slot,
@@ -412,12 +415,15 @@ static int read_cam_control(struct dvb_ca_en50221 *ca,
 {
 	struct cxd *ci = ca->data;
 	unsigned int val;
+	int ret;
 
 	mutex_lock(&ci->lock);
 	set_mode(ci, 0);
-	read_io(ci, address, &val);
+	ret = read_io(ci, address, &val);
+	if (!ret)
+		ret = val;
 	mutex_unlock(&ci->lock);
-	return val;
+	return ret;
 }
 
 static int write_cam_control(struct dvb_ca_en50221 *ca, int slot,
-- 
2.18.1


             reply	other threads:[~2020-07-22 13:41 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-22 13:41 trix [this message]
2020-09-03 14:13 ` [PATCH] media: dvb-frontends/cxd2099: report errors Mauro Carvalho Chehab
2020-09-03 14:41   ` Tom Rix

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