Re: [PATCH] PCI: xgene: Fix IB window setup

From: Krzysztof Wilczyński
Date: Tue Nov 30 2021 - 02:55:53 EST


Hi,

> Commit 6dce5aa59e0b ("PCI: xgene: Use inbound resources for setup")
> broke PCI support on XGene. The cause is the IB resources are now sorted
> in address order instead of being in DT dma-ranges order. The result is
> which inbound registers are used for each region are swapped. I don't
> know the details about this h/w, but it appears that IB region 0
> registers can't handle a size greater than 4GB. In any case, limiting
> the size for region 0 is enough to get back to the original assignment
> of dma-ranges to regions.

A small nitpick: it would be "X-Gene" in the above as per Applied Micro's
(or rather MACOM Technology Solutions these days, I suppose) product line
naming.

> @@ -465,7 +465,7 @@ static int xgene_pcie_select_ib_reg(u8 *ib_reg_mask, u64 size)
> return 1;
> }
>
> - if ((size > SZ_1K) && (size < SZ_1T) && !(*ib_reg_mask & (1 << 0))) {
> + if ((size > SZ_1K) && (size < SZ_4G) && !(*ib_reg_mask & (1 << 0))) {
> *ib_reg_mask |= (1 << 0);
> return 0;
> }

Thank you!

Reviewed-by: Krzysztof Wilczyński <kw@xxxxxxxxx>

Also, thank you Stéphane for testing! Much appreciated!

Krzysztof