From 06f25bd2a907fa543d69757da4e3c752b7103e54 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>
Date: Thu, 25 Nov 2021 11:32:43 +0100
Subject: [PATCH] pci: Disable I/O forwarding during autoconfiguration if
unsupported
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit
If U-Boot does not have any I/O resource for assignment then disable I/O
forwarding in PCI bridge autoconfiguration code. Default initial state of
PCI bridge IO registers is unspecified, therefore they can be in enabled if
U-Boot does not touch them.
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>
---
drivers/pci/pci_auto.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/pci/pci_auto.c b/drivers/pci/pci_auto.c
index 7e6ee54be0..6e5ed194f2 100644
--- a/drivers/pci/pci_auto.c
+++ b/drivers/pci/pci_auto.c
@@ -265,6 +265,14 @@ void dm_pciauto_prescan_setup_bridge(struct udevice *dev, int sub_bus)
(pci_io->bus_lower & 0xffff0000) >> 16);
cmdstat |= PCI_COMMAND_IO;
+ } else {
+ /* Disable I/O if unsupported */
+ dm_pci_write_config8(dev, PCI_IO_BASE, 0xf0 | io_32);
+ dm_pci_write_config8(dev, PCI_IO_LIMIT, 0x0 | io_32);
+ if (io_32 == PCI_IO_RANGE_TYPE_32) {
+ dm_pci_write_config16(dev, PCI_IO_BASE_UPPER16, 0x0);
+ dm_pci_write_config16(dev, PCI_IO_LIMIT_UPPER16, 0x0);
+ }
}
/* Enable memory and I/O accesses, enable bus master */
--
2.39.5