[PATCH] PCI: xgene: Fix IB window setup

Rob Herring
2021-11-29T17:38:04Z

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.

Reported-by: Stéphane Graber <stgraber@ubuntu.com>
Fixes: 6dce5aa59e0b ("PCI: xgene: Use inbound resources for setup")
Link: https://lore.kernel.org/all/CA+enf=v9rY_xnZML01oEgKLmvY1NGBUUhnSJaETmXtDtXfaczA@mail.gmail.com/
Cc: stable@vger.kernel.org # v5.5+
Signed-off-by: Rob Herring <robh@kernel.org>
---
drivers/pci/controller/pci-xgene.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/controller/pci-xgene.c b/drivers/pci/controller/pci-xgene.c
index 56d0d50338c8..d83dbd977418 100644
--- a/drivers/pci/controller/pci-xgene.c
+++ b/drivers/pci/controller/pci-xgene.c
@@ -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;
}
--
2.32.0