From: Masahiro Yamada <yamada.masahiro@socionext.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Ben Dooks <ben.dooks@codethink.co.uk>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
DTML <devicetree@vger.kernel.org>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: [Question] orphan platform data header
Date: Sun, 21 Jul 2019 23:58:32 +0900 [thread overview]
Message-ID: <CAK7LNATAhhmeKtQYJYEje3B26zy3EtdqegRL7YmbsDOJ=0HcAg@mail.gmail.com> (raw)
In-Reply-To: <CAK8P3a133ekPqkLWfC2ee0mT3iLbFzSjJ9FDokSyaX+hMVigKA@mail.gmail.com>
On Sun, Jul 21, 2019 at 11:15 PM Arnd Bergmann <arnd@arndb.de> wrote:
>
> On Sun, Jul 21, 2019 at 2:13 PM Masahiro Yamada
> <yamada.masahiro@socionext.com> wrote:
> > On Sun, Jul 21, 2019 at 6:10 PM Arnd Bergmann <arnd@arndb.de> wrote:
> > > On Sun, Jul 21, 2019 at 5:45 AM Masahiro Yamada
> > > <yamada.masahiro@socionext.com> wrote:
> > > > On Sat, Jul 20, 2019 at 10:55 PM Arnd Bergmann <arnd@arndb.de> wrote:
> > > > > On Sat, Jul 20, 2019 at 5:26 AM Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
> >
> >
> > Another example that I have no idea
> > how it works:
> >
> > drivers/net/hamradio/yam.c
> >
> > yam_ioctl() reads data from user-space,
> > but the data structures for ioctl are
> > defined in include/linux/yam.h
>
> That is different: the hardware attaches to a serial port and may well
> be usable, and the user space side just contains a copy of the header,
> see https://github.com/nwdigitalradio/ax25-tools/tree/master/yamdrv
Oh, I did not know that
user-space had a copy of that.
> > If we want to fix this, we could move it
> > to include/uapi/linux/yam.h
>
> We could do that, or just leave it alone, as nobody would
> tell the difference.
When we are changing structures in uapi,
it is very likely a red alert.
On the other hand, we can change code outside of uapi
more safely.
One benefit of uapi is we can catch the compatibility level
from the directory path.
>
> > But, if nobody has reported any problem about this,
> > it might be a good proof that nobody is using this driver.
> >
> > Maybe, can we simply drop odd drivers??
>
> Both the kernel driver and the user space side have a maintainer, and
> I see no indication that it is actually broken. The driver is clearly
> a relic from old times (earlier than 2.4) and we would not merge
> this driver today.
>
> It seems more useful to keep looking for drivers with a platform_data
> header file that is no longer included by any platform for candidates
> that may be obsolete.
OK.
Thanks.
--
Best Regards
Masahiro Yamada
WARNING: multiple messages have this Message-ID (diff)
From: Masahiro Yamada <yamada.masahiro@socionext.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: DTML <devicetree@vger.kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Ben Dooks <ben.dooks@codethink.co.uk>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: [Question] orphan platform data header
Date: Sun, 21 Jul 2019 23:58:32 +0900 [thread overview]
Message-ID: <CAK7LNATAhhmeKtQYJYEje3B26zy3EtdqegRL7YmbsDOJ=0HcAg@mail.gmail.com> (raw)
In-Reply-To: <CAK8P3a133ekPqkLWfC2ee0mT3iLbFzSjJ9FDokSyaX+hMVigKA@mail.gmail.com>
On Sun, Jul 21, 2019 at 11:15 PM Arnd Bergmann <arnd@arndb.de> wrote:
>
> On Sun, Jul 21, 2019 at 2:13 PM Masahiro Yamada
> <yamada.masahiro@socionext.com> wrote:
> > On Sun, Jul 21, 2019 at 6:10 PM Arnd Bergmann <arnd@arndb.de> wrote:
> > > On Sun, Jul 21, 2019 at 5:45 AM Masahiro Yamada
> > > <yamada.masahiro@socionext.com> wrote:
> > > > On Sat, Jul 20, 2019 at 10:55 PM Arnd Bergmann <arnd@arndb.de> wrote:
> > > > > On Sat, Jul 20, 2019 at 5:26 AM Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
> >
> >
> > Another example that I have no idea
> > how it works:
> >
> > drivers/net/hamradio/yam.c
> >
> > yam_ioctl() reads data from user-space,
> > but the data structures for ioctl are
> > defined in include/linux/yam.h
>
> That is different: the hardware attaches to a serial port and may well
> be usable, and the user space side just contains a copy of the header,
> see https://github.com/nwdigitalradio/ax25-tools/tree/master/yamdrv
Oh, I did not know that
user-space had a copy of that.
> > If we want to fix this, we could move it
> > to include/uapi/linux/yam.h
>
> We could do that, or just leave it alone, as nobody would
> tell the difference.
When we are changing structures in uapi,
it is very likely a red alert.
On the other hand, we can change code outside of uapi
more safely.
One benefit of uapi is we can catch the compatibility level
from the directory path.
>
> > But, if nobody has reported any problem about this,
> > it might be a good proof that nobody is using this driver.
> >
> > Maybe, can we simply drop odd drivers??
>
> Both the kernel driver and the user space side have a maintainer, and
> I see no indication that it is actually broken. The driver is clearly
> a relic from old times (earlier than 2.4) and we would not merge
> this driver today.
>
> It seems more useful to keep looking for drivers with a platform_data
> header file that is no longer included by any platform for candidates
> that may be obsolete.
OK.
Thanks.
--
Best Regards
Masahiro Yamada
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-07-21 14:59 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-20 3:25 [Question] orphan platform data header Masahiro Yamada
2019-07-20 3:25 ` Masahiro Yamada
2019-07-20 3:25 ` Masahiro Yamada
2019-07-20 13:54 ` Arnd Bergmann
2019-07-20 13:54 ` Arnd Bergmann
2019-07-21 3:44 ` Masahiro Yamada
2019-07-21 3:44 ` Masahiro Yamada
2019-07-21 3:44 ` Masahiro Yamada
2019-07-21 9:09 ` Arnd Bergmann
2019-07-21 9:09 ` Arnd Bergmann
2019-07-21 12:12 ` Masahiro Yamada
2019-07-21 12:12 ` Masahiro Yamada
2019-07-21 14:15 ` Arnd Bergmann
2019-07-21 14:15 ` Arnd Bergmann
2019-07-21 14:58 ` Masahiro Yamada [this message]
2019-07-21 14:58 ` Masahiro Yamada
2019-07-22 6:46 ` Enrico Weigelt, metux IT consult
2019-07-22 6:46 ` Enrico Weigelt, metux IT consult
2019-07-22 6:46 ` Enrico Weigelt, metux IT consult
2019-07-22 7:24 ` Arnd Bergmann
2019-07-22 7:24 ` Arnd Bergmann
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='CAK7LNATAhhmeKtQYJYEje3B26zy3EtdqegRL7YmbsDOJ=0HcAg@mail.gmail.com' \
--to=yamada.masahiro@socionext.com \
--cc=arnd@arndb.de \
--cc=ben.dooks@codethink.co.uk \
--cc=devicetree@vger.kernel.org \
--cc=gregkh@linuxfoundation.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=torvalds@linux-foundation.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.