Re: [PATCH v4 2.6.35-rc3] drivers/net: ks8842 driver

[David Miller <davem@davemloft.net>]

From: Andrew Morton <akpm@linux-foundation.org>
Date: Mon, 19 Jul 2010 15:17:25 -0700

> On Tue, 13 Jul 2010 10:14:34 -0700 (PDT)
> David Miller <davem@davemloft.net> wrote:
> 
>> From: David J. Choi <david.choi@micrel.com>
>> Date: Tue, 13 Jul 2010 10:09:19 -0700
>> Subject: [PATCH] drivers/net: Add Micrel KS8841/42 support to ks8842 driver
>> 
>> Body of the explanation:
>>    -support 16bit and 32bit bus width.
>>    -add device reset for ks8842/8841 Micrel device.
>>    -set 100Mbps as a default for Micrel device.
>>    -set MAC address in both MAC/Switch layer with different sequence for Micrel
>>     device, as mentioned in data sheet.
>>    -use private data to set options both 16/32bit bus width and Micrel device/
>>     Timberdale(FPGA).
>>    -update Kconfig in order to put more information about ks8842 device.
> 
> gcc says
> 
> drivers/net/ks8842.c: In function 'ks8842_handle_rx':
> drivers/net/ks8842.c:428: warning: 'status' may be used uninitialized in this function
> 
> and I think I agree with it..

I'll fix this, as below.

David Choi, I'm quite upset, this shows that you did not test the
16-bit code paths (the whole _point_ of this change) at all.  You
didn't even validate the build for new warnings.

--------------------
ks8842: Fix ks8842_tx_frame() for 16bit case.

As reported by Andrew:

drivers/net/ks8842.c: In function 'ks8842_handle_rx':
drivers/net/ks8842.c:428: warning: 'status' may be used uninitialized in this function

Just use the 32-bit status for all reads, and delete the useless
cast to 'int' when reading a u16 into 'len'.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/ks8842.c |    8 +++-----
 1 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ks8842.c b/drivers/net/ks8842.c
index ee69dea..634dad1 100644
--- a/drivers/net/ks8842.c
+++ b/drivers/net/ks8842.c
@@ -424,16 +424,14 @@ static int ks8842_tx_frame(struct sk_buff *skb, struct net_device *netdev)
 static void ks8842_rx_frame(struct net_device *netdev,
 	struct ks8842_adapter *adapter)
 {
-	u16 status16;
 	u32 status;
 	int len;
 
 	if (adapter->conf_flags & KS884X_16BIT) {
-		status16 = ks8842_read16(adapter, 17, REG_QMU_DATA_LO);
-		len  = (int)ks8842_read16(adapter, 17, REG_QMU_DATA_HI);
-		len &= 0xffff;
+		status = ks8842_read16(adapter, 17, REG_QMU_DATA_LO);
+		len = ks8842_read16(adapter, 17, REG_QMU_DATA_HI);
 		netdev_dbg(netdev, "%s - rx_data: status: %x\n",
-			   __func__, status16);
+			   __func__, status);
 	} else {
 		status = ks8842_read32(adapter, 17, REG_QMU_DATA_LO);
 		len = (status >> 16) & 0x7ff;
-- 
1.7.1.1