Re: [PATCH RESEND 2/2] arm64: dts: rockchip: Add RGA2 support to rk356x

From: Shengyu Qu
Date: Fri Feb 17 2023 - 09:20:13 EST


Hi Michael,

Seems we could use GFP_DMA32 flag to limit memory required by driver into

upper size range(actually using ZONE_DMA32 configured by device tree). Just

some driver modification needed. Maybe Nicolas could help testing? I would

like to fix this, but I don't have much free time these days.

Best regards,

Shengyu

Hi,

On Sun, 22 Jan 2023 00:50:37 +0800, Shengyu Qu wrote:
Since we have the over-4GB problem now, should we mark this problem as a
TODO or something?
I am not really sure where to put such a TODO to make it visible for people
that are running into the issue and to make sure that it is removed once it is
fixed.

Maybe it would be better to add error handling to the rga_buf_map function to
fail if the address of the buffer that should be mapped has the upper 32 bit
set and print a warning. Furthermore, the driver would be able to skip the
buffer and prevent potential memory corruption caused by the erroneous
mapping.

Unfortunately, I don't have hardware that allows me to test this.

Michael

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