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 10:09:50 +0800 [thread overview]
Message-ID: <5258AF6E.9010708@asianux.com> (raw)
In-Reply-To: <5258A7AC.4060902@asianux.com>
On 10/12/2013 09:36 AM, Chen Gang wrote:
> 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).
>
For "./kernel" sub-system, it really it is, if necessary, I can provide
3 samples. ;-)
>
>
> Thanks.
>
>> Thanks,
>> //richard
>>
>>
>>
>
--
Chen Gang
next prev parent reply other threads:[~2013-10-12 2:10 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
2013-10-12 2:09 ` Chen Gang [this message]
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5258AF6E.9010708@asianux.com \
--to=gang.chen@asianux.com \
--cc=Catalin.Marinas@arm.com \
--cc=heiko.carstens@de.ibm.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-s390@vger.kernel.org \
--cc=linux390@de.ibm.com \
--cc=linux@arm.linux.org.uk \
--cc=richard.weinberger@gmail.com \
--cc=richard@nod.at \
--cc=schwidefsky@de.ibm.com \
--cc=will.deacon@arm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox