Re: [PATCH v4 1/5] of_address: Add bus type match for pci ranges parser
From: Rob Herring <robh+dt@kernel.org>
Date: 2020-08-14 22:51:33
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On Fri, Aug 14, 2020 at 12:21 PM Marc Zyngier [off-list ref] wrote:
Hi all, On 2020-07-28 16:36, Jiaxun Yang wrote:quoted
So the parser can be used to parse range property of ISA bus. As they're all using PCI-like method of range property, there is no need start a new parser. Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Reviewed-by: Rob Herring <robh@kernel.org>This patch, although it looks correct, breaks the RK3399-based systems, as they miss the (now required) 'device_type = "pci";' property.
Required since 1990 something...
We can fix the in-tree DT, but that's not really an option if someone relies on the DT being provided by the firmware (I for one definitely do).
Perhaps time to pay attention to schema errors: arch/arm64/boot/dts/rockchip/rk3399-sapphire-excavator.dt.yaml: pcie@f8000000: 'device_type' is a required property (I thought dtc would also catch this, but there we look for device_type and then do PCI checks like node name. I guess we needed to check for either device_type or the node name...)
quoted hunk ↗ jump to hunk
I came up with the following hack, which solves the issue for me. Definitely not my finest hour, but I really need this box to keep going. I will post a patch fixing the DT separately. Thanks, M. From ceef5fd9c4d2005eb577505c68868ebe527c098f Mon Sep 17 00:00:00 2001 From: Marc Zyngier [off-list ref] Date: Fri, 14 Aug 2020 19:10:12 +0100 Subject: [PATCH] of: address: Workaround broken DTs missing the 'device_type = "pci"' property Recent changes to the PCI bus parsing made it mandatory for device trees nodes describing a PCI controller to have the 'device_type = "pci"' property for the node to be matched. Although this is compliant with the specification, it breaks existing device-trees that have been working fine for years (the Rockchip rk3399-based systems being a prime example of such breakage). In order to paper over the blunder, let's also match nodes that have the "linux,pci-domain" property, as they are pretty likely to be PCI nodes. This fixes the issue for systems such as the above platforms. Fixes: 2f96593ecc37 ("of_address: Add bus type match for pci ranges parser") Signed-off-by: Marc Zyngier <maz@kernel.org> --- drivers/of/address.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)diff --git a/drivers/of/address.c b/drivers/of/address.c index 590493e04b01..712e03781a2a 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c@@ -134,9 +134,12 @@ static int of_bus_pci_match(struct device_node *np) * "pciex" is PCI Express * "vci" is for the /chaos bridge on 1st-gen PCI powermacs * "ht" is hypertransport + * "linux,pci-domain" is a workaround for broken device trees + * lacking the required "device_type" property.
I would suggest looking for 'pci' or 'pcie' node name instead. You should remove linux,pci-domain from rk3399 as it is pointless when there's a single PCI host bridge. The other option is fixup the live tree with of_add_property() in the Rockchip PCI driver. Less likely to impact anyone else.
*/
return of_node_is_type(np, "pci") || of_node_is_type(np, "pciex") ||
- of_node_is_type(np, "vci") || of_node_is_type(np, "ht");
+ of_node_is_type(np, "vci") || of_node_is_type(np, "ht") ||
+ of_find_property(np, "linux,pci-domain", NULL);
}
static void of_bus_pci_count_cells(struct device_node *np,
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2.27.0
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Jazz is not dead. It just smells funny...