RPi4B: emmc2bus dma-range handling does not track the boot-time-FDT (u-boot based booting)

[Klaus Cucinauomo]

> Am 09.10.2020 um 14:55 schrieb Kyle Evans <kevans at freebsd.org>:
>>>> 
>> 
>> Another type of overall issue (that may not apply to
>> the specific context here) is dtb content like:
>> 
>>        scb {
>>                compatible = "simple-bus";
>>                #address-cells = <0x00000002>;
>>                #size-cells = <0x00000002>;
>>                ranges = * 0x0000000007ef8a18 [0x00000060];
>>                dma-ranges = <0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0xfc000000 0x00000001 0x00000000 0x00000001 0x00000000 0x00000001 0x00000000>;
>>                phandle = <0x000000d0>;
>>                pcie at 7d500000 {
>>                        compatible = "brcm,bcm2711-pcie";
>>                        . . .
>>                        #address-cells = <0x00000003>;
>>                        #interrupt-cells = <0x00000001>;
>>                        #size-cells = <0x00000002>;
>>                        . . .
>>                        dma-ranges = <0x02000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0xc0000000>;
>>                        . . .
>>                };
>>                . . .
>> 
>> where the inner most dma-ranges is not from the just-surrounding
>> context (parent) but is strictly local (despite the parent
>> potentially also having dma-ranges). I think that only pcie at ...
>> is that way so far for the RPi4 --but notationally it seems to
>> be generally allowed.
>> 
> 
> This is irrelevant for the time being as the PCI driver doesn't cross
> paths with the snippet the patch touches.
> 
> Thanks,
> 
> Kyle Evans
> 


Yes, dma is another topic… thanks for working on RPI again !,

external links to the xhci-initializiation - issue for the 8GB-model in u-boot 2020.10 :

http://u-boot.10912.n7.nabble.com/PATCH-v6-0-4-usb-xhci-Load-Raspberry-Pi-4-VL805-s-firmware-td418114.html

https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg2205783.html

https://patchwork.ozlabs.org/project/linux-pci/patch/20200629161845.6021-4-nsaenzjulienne@suse.de/

https://patchwork.ozlabs.org/project/linux-pci/patch/20200629161845.6021-5-nsaenzjulienne@suse.de/

`guess there will be some other DeviceTree-adjustments needed to boot directly off of an SSD until reaching the root-login.

Regards
K.