Date:   Tue, 6 Oct 2020 07:16:33 +0800
From:   Chun-Kuang Hu <chunkuang.hu@...nel.org>
To:     Rob Herring <robh+dt@...nel.org>
Cc:     Phil Chang <phil.chang@...iatek.com>,
        Chun-Kuang Hu <chunkuang.hu@...nel.org>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        DTML <devicetree@...r.kernel.org>,
        Alix Wu <alix.wu@...iatek.com>,
        YJ Chiang <yj.chiang@...iatek.com>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@...ts.infradead.org>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Joe Liu <joe.liu@...iatek.com>,
        Frank Rowand <frowand.list@...il.com>
Subject: Re: [PATCH] [PATCH] of_reserved_mem: Increase the number of reserved regions

Rob Herring <robh+dt@...nel.org> 於 2020年10月6日 週二 上午2:57寫道：
>
> On Mon, Oct 5, 2020 at 12:17 PM Phil Chang <phil.chang@...iatek.com> wrote:
> >
> > Hi Chun-Kuang
>
> Please don't top post to the lists.
>
> > Sorry for typo. In fact, the dts of new SoC is not upstream yet. I'm so
> > sorry for couldn't show the detail now.
>
> Don't have to have the dts upstream. Can you point to a downstream dts
> or post a snippet of the reserved memory?
>
> > How about the configurable MAX_RESERVED_REGIONS size like this patch?
> > https://patchwork.kernel.org/patch/10692101/
>
> No, as I already said in that patch. But glad you found what's needed
> to make it dynamic. But even for dynamic, I want to understand the
> use.

I get the point. We should prevent too many config. If this
information could be get from dts, we should not get it from config.
Agree that WHY of this patch is more important than HOW of this patch.

Regards,
Chun-Kuang.

>
> Rob
>
> >
> >
> > On Sun, 2020-10-04 at 21:05 +0800, Chun-Kuang Hu wrote:
> > > Hi, Phil:
> > >
> > > Phil Chang <phil.chang@...iatek.com> 於 2020年10月4日 週日 下午1:51寫道：
> > > >
> > > > Certain SoCs need to support large amount of reserved memory
> > > > regions, especially to follow the GKI rules from Google.
> > > > In MTK new SoC requires more than 68 regions of reserved memory
> > > > for each IP's usage, such as load firmware to specific sapce,
> > >
> > > space
> > >
> > > > so that need to reserve more regisions
> > >
> > > regions.
> > >
> > > I guess this requirement is from Mediatek SoC, but I find below device
> > > tree and just find one reserved memory region,
> > >
> > > arch/arm64/boot/dts/mediatek/mt7622.dtsi
> > > arch/arm64/boot/dts/mediatek/mt8173.dtsi
> > > arch/arm64/boot/dts/mediatek/mt8516.dtsi
> > >
> > > Could you show me the 68 regions?
> > >
> > > Regards,
> > > Chun-Kuang.
> > >
> > > >
> > > > Signed-off-by: Joe Liu <joe.liu@...iatek.com>
> > > > Signed-off-by: YJ Chiang <yj.chiang@...iatek.com>
> > > > Signed-off-by: Alix Wu <alix.wu@...iatek.com>
> > > > Signed-off-by: Phil Chang <phil.chang@...iatek.com>
> > > > ---
> > > >  drivers/of/of_reserved_mem.c | 2 +-
> > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
> > > > index 46b9371c8a33..595f0741dcef 100644
> > > > --- a/drivers/of/of_reserved_mem.c
> > > > +++ b/drivers/of/of_reserved_mem.c
> > > > @@ -22,7 +22,7 @@
> > > >  #include <linux/slab.h>
> > > >  #include <linux/memblock.h>
> > > >
> > > > -#define MAX_RESERVED_REGIONS   64
> > > > +#define MAX_RESERVED_REGIONS   128
> > > >  static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
> > > >  static int reserved_mem_count;
> > > >
> > > > --
> > > > 2.18.0
> > > > _______________________________________________
> > > > Linux-mediatek mailing list
> > > > Linux-mediatek@...ts.infradead.org
> > > > http://lists.infradead.org/mailman/listinfo/linux-mediatek
> >

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