linux-kernel - [PATCHv2] mfd: twl4030: clarify the return value for read and write

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed,  2 Dec 2009 16:00:50 +0200
From:	Amit Kucheria <amit.kucheria@...durent.com>
To:	List Linux Kernel <linux-kernel@...r.kernel.org>
Cc:	Samuel Ortiz <sameo@...ux.intel.com>,
	List Linux Omap <linux-omap@...r.kernel.org>
Subject: [PATCHv2] mfd: twl4030: clarify the return value for read and write

Infact, we can just return -1 so that caller knows for sure that all messages
were not tranferred. Please consider fixed patch instead.

We should be checking if all the messages were tranferred or not. And return
-1 for failure. Currently we return success (0) even if none of messages were
transferred successfully.

Signed-off-by: Amit Kucheria <amit.kucheria@...durent.com>
---
 drivers/mfd/twl4030-core.c |   25 +++++++++++++++++--------
 1 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/drivers/mfd/twl4030-core.c b/drivers/mfd/twl4030-core.c
index 56f1de5..8f9ba79 100644
--- a/drivers/mfd/twl4030-core.c
+++ b/drivers/mfd/twl4030-core.c
@@ -292,10 +292,14 @@ int twl4030_i2c_write(u8 mod_no, u8 *value, u8 reg, unsigned num_bytes)
 	ret = i2c_transfer(twl->client->adapter, twl->xfer_msg, 1);
 	mutex_unlock(&twl->xfer_lock);
 
-	/* i2cTransfer returns num messages.translate it pls.. */
-	if (ret >= 0)
-		ret = 0;
-	return ret;
+	/* i2c_transfer returns number of messages transferred */
+	if (ret != 1) {
+		pr_err("%s: i2c_write failed to transfer all messages\n",
+			DRIVER_NAME);
+		return -1;
+	} else {
+		return 0;
+	}
 }
 EXPORT_SYMBOL(twl4030_i2c_write);
 
@@ -344,10 +348,15 @@ int twl4030_i2c_read(u8 mod_no, u8 *value, u8 reg, unsigned num_bytes)
 	ret = i2c_transfer(twl->client->adapter, twl->xfer_msg, 2);
 	mutex_unlock(&twl->xfer_lock);
 
-	/* i2cTransfer returns num messages.translate it pls.. */
-	if (ret >= 0)
-		ret = 0;
-	return ret;
+	/* i2c_transfer returns number of messages transferred */
+	if (ret != 2) {
+		pr_err("%s: i2c_read failed to transfer all messages\n",
+			DRIVER_NAME);
+		return -1;
+	}
+	else {
+		return 0;
+	}
 }
 EXPORT_SYMBOL(twl4030_i2c_read);
 
-- 
1.6.3.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/