linux-kernel - Re: [PATCH v4 2/6] remoteproc/mediatek: add SCP support for mt8183

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] [day] [month] [year] [list]

Date:   Wed, 13 Feb 2019 09:01:05 -0800
From:   Matthias Kaehlcke <mka@...omium.org>
To:     Pi-Hsun Shih <pihsun@...omium.org>
Cc:     Erin Lo <erin.lo@...iatek.com>,
        Nicolas Boichat <drinkcat@...omium.org>,
        Ohad Ben-Cohen <ohad@...ery.com>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Matthias Brugger <matthias.bgg@...il.com>,
        open list <linux-kernel@...r.kernel.org>,
        "open list:REMOTE PROCESSOR (REMOTEPROC) SUBSYSTEM" 
        <linux-remoteproc@...r.kernel.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-arm-kernel@...ts.infradead.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@...ts.infradead.org>
Subject: Re: [PATCH v4 2/6] remoteproc/mediatek: add SCP support for mt8183

On Wed, Feb 13, 2019 at 11:20:18AM +0800, Pi-Hsun Shih wrote:
> Hi,
> 
> Thanks for the review, would address most comments in next version of patch.
> 
> On Sat, Feb 2, 2019 at 8:17 AM Matthias Kaehlcke <mka@...omium.org> wrote:
> >
> > Hi Pi-Hsun,
> >
> > a few comments inline.
> >
> > It's the first time I dabble into remoteproc, I don't claim to have a
> > complete understanding of the driver at this point ;-)
> >
> > On Thu, Jan 31, 2019 at 05:31:27PM +0800, Pi-Hsun Shih wrote:
> > > diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
> > > new file mode 100644
> > > index 00000000000000..920c81c3525c2a
> > > --- /dev/null
> > > +++ b/drivers/remoteproc/mtk_scp.c
> > > +             return ret;
> > > +     }
> > > +
> > > +     writel(0x0, scp->reg_base + MT8183_SCP_SRAM_PDN);
> >
> > what is the purpose of this write?
> >
> 
> Answer from Erin:
> The code needs to execute on scp’s SRAM.
> We need to turn on the power of SRAM before using it.

Please add a brief comment since this is not evident from the code.

Thanks

Matthias