Subject: Re: linux-next: build warning in Linus' tree

From: David Miller <[email-masked]>
Date: Tue, 25 May 2010 16:19:29 -0700 (PDT)

From: David Miller <[email-masked]>
Date: Mon, 24 May 2010 21:58:22 -0700 (PDT)

> From: Stephen Rothwell <[email-masked]>
> Date: Tue, 25 May 2010 11:46:14 +1000
> 
>> Hi Dave,
>> 
>> Today's linux-next build (x86_64 allmodconfig) produced this warning:
>> 
>> drivers/net/usb/asix.c: In function 'asix_rx_fixup':
>> drivers/net/usb/asix.c:325: warning: cast from pointer to integer of different size
>> drivers/net/usb/asix.c:354: warning: cast from pointer to integer of different size
>> 
>> Introduced by commit 3f78d1f210ff89af77f042ab7f4a8fee39feb1c9
>> ("drivers/net/usb/asix.c: Fix unaligned accesses").  This commit casts
>> skb->data to u32.
> 
> Thanks I'll look into this.

Here is how I fixed this:

--------------------
drivers/net/usb/asix.c: Fix pointer cast.

Stephen Rothwell reports the following new warning:

drivers/net/usb/asix.c: In function 'asix_rx_fixup':
drivers/net/usb/asix.c:325: warning: cast from pointer to integer of different size
drivers/net/usb/asix.c:354: warning: cast from pointer to integer of different size

The code just cares about the low alignment bits, so use
an "unsigned long" cast instead of one to "u32".

Signed-off-by: David S. Miller <[email-masked]>
---
 drivers/net/usb/asix.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/net/usb/asix.c b/drivers/net/usb/asix.c
index 31b7331..ea75f47 100644
--- a/drivers/net/usb/asix.c
+++ b/drivers/net/usb/asix.c
@@ -322,7 +322,7 @@ static int asix_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 		size = (u16) (header & 0x0000ffff);
 
 		if ((skb->len) - ((size + 1) & 0xfffe) == 0) {
-			u8 alignment = (u32)skb->data & 0x3;
+			u8 alignment = (unsigned long)skb->data & 0x3;
 			if (alignment != 0x2) {
 				/*
 				 * not 16bit aligned so use the room provided by
-- 
1.7.0.4