linux-kernel - Re: [PATCH v3 1/3] memory: tegra: Add devm_tegra_get_memory

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: <20200930160355.GC3833404@ulmo>
Date:   Wed, 30 Sep 2020 18:03:55 +0200
From:   Thierry Reding <thierry.reding@...il.com>
To:     Dmitry Osipenko <digetx@...il.com>
Cc:     Nicolin Chen <nicoleotsuka@...il.com>, joro@...tes.org,
        krzk@...nel.org, vdumpa@...dia.com, jonathanh@...dia.com,
        linux-tegra@...r.kernel.org, iommu@...ts.linux-foundation.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 1/3] memory: tegra: Add
 devm_tegra_get_memory_controller()

On Wed, Sep 30, 2020 at 06:53:06PM +0300, Dmitry Osipenko wrote:
> 30.09.2020 18:23, Thierry Reding пишет:
> > On Wed, Sep 30, 2020 at 01:42:56AM -0700, Nicolin Chen wrote:
> >> From: Dmitry Osipenko <digetx@...il.com>
> >>
> >> Multiple Tegra drivers need to retrieve Memory Controller and hence there
> >> is quite some duplication of the retrieval code among the drivers. Let's
> >> add a new common helper for the retrieval of the MC.
> >>
> >> Signed-off-by: Dmitry Osipenko <digetx@...il.com>
> >> Signed-off-by: Nicolin Chen <nicoleotsuka@...il.com>
> >> ---
> >>
> >> Changelog
> >> v2->v3:
> >>  * Replaced with Dimtry's devm_tegra_get_memory_controller()
> >> v1->v2:
> >>  * N/A
> >>
> >>  drivers/memory/tegra/mc.c | 39 +++++++++++++++++++++++++++++++++++++++
> >>  include/soc/tegra/mc.h    | 17 +++++++++++++++++
> >>  2 files changed, 56 insertions(+)
> > 
> > Let's not add this helper, please. If a device needs a reference to the
> > memory controller, it should have a phandle to the memory controller in
> > device tree so that it can be looked up explicitly.
> > 
> > Adding this helper is officially sanctioning that it's okay not to have
> > that reference and that's a bad idea.
> 
> And please explain why it's a bad idea, I don't see anything bad here at
> all.

Well, you said yourself in a recent comment that we should avoid global
variables. devm_tegra_get_memory_controller() is nothing but a glorified
global variable.

Thierry

Download attachment "signature.asc" of type "application/pgp-signature" (834 bytes)