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Subject: BOG: commit 89c7cb1608ac3 ("of/device: Update dma_range_map only when dev has valid dma-ranges") seems to break Pinephone display or LCDC
From:   "H. Nikolaus Schaller" <hns@goldelico.com>
Date:   Tue, 2 Feb 2021 10:18:02 +0100
Cc:     Frank Rowand <frowand.list@gmail.com>,
        Rob Herring <robh@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        Discussions about the Letux Kernel 
        <letux-kernel@openphoenux.org>
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Message-Id: <81FE44A3-38C8-4B78-BB77-C09B4FC80B0A@goldelico.com>
To:     Robin Murphy <robin.murphy@arm.com>,
        Yong Wu <yong.wu@mediatek.com>,
        Paul Kocialkowski <paul.kocialkowski@bootlin.com>,
        Rob Herring <robh@kernel.org>
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Hi,
since v5.11-rc6 my Pinephone display shows some moir=C3=A9 pattern.

I did a bisect between v5.11-rc5 and v5.11-rc6 and it told me that
the commit mentioned in the subject is the reason.

Reverting it makes the display work again and re-reverting fail again.

IMHO it seems as if the display DMA of the pinephone (allwinner =
suni-a54)
got influenced and stopped to scan the framebuffer.

The only dma-ranges I could find are defined here:

	arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi

	dma-ranges =3D <0x00000000 0x40000000 0xc0000000>;

but I can't tell if they are "valid" or not.

Any insights are welcome. And please direct to the right people/mailing =
lists
if they are missing.

BR and thanks,
Nikolaus Schaller