From: Chen Gang <gang.chen@asianux.com>
To: Richard Weinberger <richard@nod.at>
Cc: Will Deacon <will.deacon@arm.com>,
Richard Weinberger <richard.weinberger@gmail.com>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Russell King - ARM Linux <linux@arm.linux.org.uk>,
Catalin Marinas <Catalin.Marinas@arm.com>,
"linux390@de.ibm.com" <linux390@de.ibm.com>,
"linux-s390@vger.kernel.org" <linux-s390@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] arm/arm64: remove atomic_clear_mask() in "include/asm/atomic.h"
Date: Sat, 12 Oct 2013 09:36:44 +0800 [thread overview]
Message-ID: <5258A7AC.4060902@asianux.com> (raw)
In-Reply-To: <5257F710.5090706@nod.at>
On 10/11/2013 09:03 PM, Richard Weinberger wrote:
> Am 11.10.2013 14:28, schrieb Will Deacon:
>> On Fri, Oct 11, 2013 at 01:08:17PM +0100, Richard Weinberger wrote:
>>> On Fri, Oct 11, 2013 at 1:47 PM, Chen Gang <gang.chen@asianux.com> wrote:
>>>> In current kernel wide source code, except other architectures, only
>>>> s390 scsi drivers use atomic_clear_mask(), and arm/arm64 need not
>>>> support s390 drivers.
>>>>
>>>> So remove atomic_clear_mask() from "arm[64]/include/asm/atomic.h".
>>>
>>> Is it really worth removing such a primitive?
>>> If someone needs it later he has to implement it from scratch and
>>> introduces bugs...
>>
>> The version we have (on ARM64 anyway) already has bugs. Given the choice
>> between fixing code that has no callers and simply removing it, I'd go for
>> the latter.
>
> Yeah, if it's broken and has no real users, send it to hell. :)
>
OK, thanks.
Hmm... at least, the original API definition is not well enough: "need
use 'unsigned int' and 'atomic_t' instead of 'unsigned long' for the
type of parameters".
But can we say "under arm64, it must be a bug"? (although I agree it is
very easy to let callers miss using it -- then may cause issue).
In my opinion, it belongs to "API definition issue" not implementation
bug: "if all callers are carefully enough, it will not make issues"
(e.g. in "./kernel" sub-system, we can meet many such kinds of things).
Thanks.
> Thanks,
> //richard
>
>
>
--
Chen Gang
next prev parent reply other threads:[~2013-10-12 1:37 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-10 2:30 [PATCH 0/3] s390/arm/arm64: include: asm: atomic.h: use 'unsigned int' and 'atomic_t' instead of 'unsigned long' for atomic_*_mask() Chen Gang
2013-10-10 2:31 ` [PATCH 1/3] s390: include: asm: atomic.h: use 'unsigned int' " Chen Gang
2013-10-10 2:34 ` [PATCH 2/3] arm: include: asm: atomic.h: use 'unsigned int' and 'atomic' instead of 'unsigned long' for atomic_clear_mask() Chen Gang
2013-10-10 2:35 ` [PATCH 3/3] arm64: include: asm: atomic.h: use 'unsigned int' and 'atomic_t' " Chen Gang
2013-10-10 10:07 ` Will Deacon
2013-10-10 11:03 ` Chen Gang
2013-10-10 14:23 ` Will Deacon
2013-10-11 1:18 ` Chen Gang
2013-10-11 10:44 ` Will Deacon
2013-10-11 11:25 ` Chen Gang
2013-10-11 11:47 ` [PATCH] arm/arm64: remove atomic_clear_mask() in "include/asm/atomic.h" Chen Gang
2013-10-11 12:08 ` Richard Weinberger
2013-10-11 12:28 ` Will Deacon
2013-10-11 13:03 ` Richard Weinberger
2013-10-12 1:36 ` Chen Gang [this message]
2013-10-12 2:09 ` Chen Gang
2013-10-11 16:55 ` Will Deacon
2013-10-12 1:46 ` Chen Gang
2013-10-12 22:28 ` Catalin Marinas
2013-10-10 9:58 ` [PATCH 2/3] arm: include: asm: atomic.h: use 'unsigned int' and 'atomic' instead of 'unsigned long' for atomic_clear_mask() Will Deacon
2013-10-10 11:02 ` Chen Gang
2013-10-10 7:25 ` [PATCH 1/3] s390: include: asm: atomic.h: use 'unsigned int' instead of 'unsigned long' for atomic_*_mask() Heiko Carstens
2013-10-10 7:34 ` Chen Gang
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