Linux Kernel • Re: Suspicious line in bcm2835_dma.c

I see, many thanks for the update. Btw, should the line https://github.com/6by9/linux/blob/eb3b ... ma.c#L1360
be 40 bit instead, as the one from this commit: https://github.com/6by9/linux/blob/a106 ... ma.c#L1432

It's academic as there are no Pi boards above 64GB.
I think technically the DMA controller supports 40-bit addresses, but the sdram controller and other parts of infrastructure mean all those bit cannot be used.

I'd already had exactly that discussion with Dom and PhilE, as 2711 was heading to be 36 bit with 2712 being 40 bit.
It will be unified at 40 bit in the final version as the hardware could in theory do it, but reality is it will never be needed.

Statistics: Posted by 6by9 — Fri Mar 01, 2024 2:38 pm

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