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Date:   Wed, 16 Nov 2022 10:06:29 +0100
From:   Frank Wunderlich <frank-w@public-files.de>
To:     Daniel Golle <daniel@makrotopia.org>
CC:     linux-mediatek@lists.infradead.org, devicetree@vger.kernel.org,
        Ryder Lee <ryder.lee@mediatek.com>,
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        Kishon Vijay Abraham I <kishon@ti.com>,
        Jianjun Wang <jianjun.wang@mediatek.com>,
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        Lorenzo Bianconi <lorenzo@kernel.org>,
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Subject: Re: [PATCH v4 10/11] arm64: dts: mt7986: add Bananapi R3
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Am 15=2E November 2022 23:01:20 MEZ schrieb Daniel Golle <daniel@makrotopia=
=2Eorg>:


>The device can boot from all 4 storage options=2E Both, SPI and MMC, can
>be switched using hardware switches on the board, see
>https://wiki=2Ebanana-pi=2Eorg/Banana_Pi_BPI-R3#Jumper_setting
>
>So why do the SPI-NAND vs=2E SPI-NOR switching with device tree overlays
>and the SD card vs=2E eMMC switching with dtsi + 2x dts? To me this looks
>inconsitent=2E Use either one or the other method=2E

Hi Daniel

It is still in discussion,if mainline-kernel will support devicetree-overl=
ays [1]=2E

I used this way to have at least 1 dtb without overlay for booting kernel =
from sdcard which is the only external storage=2E

If mainline kernel rejects dto, we have no "broken" dtb which only allows =
bootup with initrd=2E We can boot this board from sdcard with mainline code=
 only (maybe some users don't need emmc,nand,nor)=2E

As you cannot delete (sd specific) properties in overlays,i added emmc var=
iant=2E And now we can use overlays to support spi devices,which are not ne=
eded for first bootup,but to access emmc=2E

Imho my current sd/emmc dts can be easily converted to dtso and base dtsi =
needs only to be renamed=2E But all only if the big question below is answe=
red=2E

[1] https://patchwork=2Ekernel=2Eorg/project/linux-mediatek/patch/20221106=
085034=2E12582-12-linux@fw-web=2Ede/#25085681

regards Frank