On 10/03/2020 18:16, Robin Murphy wrote:
On 10/03/2020 3:48 pm, Tony Lindgren wrote:
* Tero Kristo <t-kristo@xxxxxx> [200310 14:46]:
On 10/03/2020 13:53, Roger Quadros wrote:
The L3 interconnect can access only 32-bits of address.
Add the dma-ranges property to reflect this limit.
This will ensure that no device under L3 is
given > 32-bit address for DMA.
Issue was observed only with SATA on DRA7-EVM with 4GB RAM
and CONFIG_ARM_LPAE enabled. This is because the controller
can perform 64-bit DMA and was setting the dma_mask to 64-bit.
Setting the correct bus_dma_limit fixes the issue.
This seems kind of messy to modify almost every DT node because of this....
Are you sure this is the only way to get it done? No way to modify the sata
node only which is impacted somehow?
Also, what if you just pass 0xffffffff to the dma-ranges property? That
would avoid modifying every node I guess.
Also, I think these interconnects are not limited to 32-bit access.
So yeah I too would prefer a top level dma-ranges property assuming
that works.
I guess there dma-ranges should not be 0xffffffff though if
limited to 2GB :)
Right, and the code expects it to not look like a mask.
From of_dma_configure()
ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
..
if (size & 1) {
dev_warn(dev, "Invalid size 0x%llx for dma-range\n",
size);
size = size + 1;
}
It should work fine to just describe the Q3 and Q4 DDR regions as the DMA range, i.e.:
ocp {
...
dma-ranges = <0x80000000 0 0x80000000 0x80000000>;
...
};
That would certainly be far less invasive :)
This is brilliant! Thanks :)
--
cheers,
-roger
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