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Subject: Re: [PATCH 4/4] zd1211rw: remove unnecessary [kv][mcz]alloc casts
From: Joe Perches <joe@perches.com>
To: Johannes Berg <johannes@sipsolutions.net>
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Date: Sun, 28 Nov 2010 02:13:52 -0800
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On Sun, 2010-11-28 at 11:02 +0100, Johannes Berg wrote:
> On Sun, 2010-11-28 at 01:50 -0800, Joe Perches wrote:
> > Good memory you have Johannes...
> > http://marc.info/?l=linux-netdev&m=117113743902549&w=3
> I, err, not really, all this isn't making a whole lot of sense to me
> right now :-)
> The only thing I remembered was that there was something weird with
> zd_addr_t ...

Yes.  It's marked __nocast.

> Did sparse become more reliable in face of errors?

Apparently not.

If the kmalloc cast in zd_chip is removed:

$ make C=1 drivers/net/wireless/zd1211rw/zd_chip.o
  CHK     include/linux/version.h
  CHK     include/generated/utsrelease.h
  CALL    scripts/checksyscalls.sh
  CHECK   drivers/net/wireless/zd1211rw/zd_chip.c
arch/x86/include/asm/uaccess_32.h:197:9: error: attribute 'error': unknown attribute
  CC      drivers/net/wireless/zd1211rw/zd_chip.o
$

If the __compiletime_<foo> uses in uaccess_32.h are removed,
and the kmalloc cast in zd_chip is also removed:

$ make C=1 drivers/net/wireless/zd1211rw/zd_chip.o
  CHK     include/linux/version.h
  CHK     include/generated/utsrelease.h
  CC      arch/x86/kernel/asm-offsets.s
  GEN     include/generated/asm-offsets.h
  CALL    scripts/checksyscalls.sh
  CHECK   drivers/net/wireless/zd1211rw/zd_chip.c
drivers/net/wireless/zd1211rw/zd_chip.c:121:22: warning: implicit cast to nocast type
  CC      drivers/net/wireless/zd1211rw/zd_chip.o
$