linux-kernel - Re: [RFC PATCH 2/3] regmap: Add reg_update

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CADBw62p0O6dfiMF_r0SaN3cvrmcUdmnLm55gv_c=pywwzpTjoQ@mail.gmail.com>
Date:   Thu, 9 Apr 2020 22:12:44 +0800
From:   Baolin Wang <baolin.wang7@...il.com>
To:     Mark Brown <broonie@...nel.org>
Cc:     Lee Jones <lee.jones@...aro.org>, Arnd Bergmann <arnd@...db.de>,
        Orson Zhai <orsonzhai@...il.com>,
        Chunyan Zhang <zhang.lyra@...il.com>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [RFC PATCH 2/3] regmap: Add reg_update_bits() support

Hi Mark,

On Thu, Apr 9, 2020 at 6:45 PM Mark Brown <broonie@...nel.org> wrote:
>
> On Thu, Apr 09, 2020 at 04:57:58PM +0800, Baolin Wang wrote:
> > Add reg_update_bits() support in case some platforms use a special method
> > to update bits of registers.
> >
> > Signed-off-by: Baolin Wang <baolin.wang7@...il.com>
> > ---
> >  drivers/base/regmap/regmap-mmio.c | 29 ++++++++++++++++++++++++++++-
> >  drivers/base/regmap/regmap.c      |  1 +
>
> MMIO devices clearly don't physically have an update_bits() operation so
> this should be implemented further up the stack where it applies to all
> buses without physical support.

I understood your concern. But the syscon driver need use the MMIO
devices' resources (such as address mapping, clock management and so
on), if move this to further up stack, I am afraid the update_bits()
can not use the resources in 'struct regmap_mmio_context'. Do you have
any good suggestion? Thanks.

-- 
Baolin Wang