[Bug 220479] New: [regression 6.16] mvebu: no pci devices detected on turris omnia

[Klaus Kudielka]

On Thu, 2025-08-21 at 02:45 +0200, Jan Palus wrote:
> 
> Relevant fragment of mvebu_get_tgt_attr() in mentioned commit:
> 
> +		u32 slot = upper_32_bits(range.bus_addr);
>  
> -		if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_IO)
> +		if (DT_FLAGS_TO_TYPE(range.flags) == DT_TYPE_IO)
>  			rtype = IORESOURCE_IO;
> -		else if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_MEM32)
> +		else if (DT_FLAGS_TO_TYPE(range.flags) == DT_TYPE_MEM32)
>  			rtype = IORESOURCE_MEM;
>  		else
>  			continue;
>  
>  		if (slot == PCI_SLOT(devfn) && type == rtype) {
> 

As far as I understand the situation, of_pci_range_parser_one() inherently uses bus->get_flags()
aka of_bus_pci_get_flags() to determine range.flags (see drivers/of/address.c).

And of_bus_pci_get_flags() does essentially the same thing as the code above in mvebu_get_tgt_attr().
So, now the translation logic is applied twice - which probably was not intended.

To restore the original behaviour, I think the determination of rtype from range.flags must be 
completely removed, and rtype must be replaced by range.flags.

Something like this on top of mainline - completely untested, but maybe worth a try.

diff --git a/drivers/pci/controller/pci-mvebu.c b/drivers/pci/controller/pci-mvebu.c
index 755651f338..3fce4a2b63 100644
--- a/drivers/pci/controller/pci-mvebu.c
+++ b/drivers/pci/controller/pci-mvebu.c
@@ -1168,9 +1168,6 @@ static void __iomem *mvebu_pcie_map_registers(struct platform_device *pdev,
        return devm_ioremap_resource(&pdev->dev, &port->regs);
 }
 
-#define DT_FLAGS_TO_TYPE(flags)       (((flags) >> 24) & 0x03)
-#define    DT_TYPE_IO                 0x1
-#define    DT_TYPE_MEM32              0x2
 #define DT_CPUADDR_TO_TARGET(cpuaddr) (((cpuaddr) >> 56) & 0xFF)
 #define DT_CPUADDR_TO_ATTR(cpuaddr)   (((cpuaddr) >> 48) & 0xFF)
 
@@ -1189,17 +1186,9 @@ static int mvebu_get_tgt_attr(struct device_node *np, int devfn,
                return -EINVAL;
 
        for_each_of_range(&parser, &range) {
-               unsigned long rtype;
                u32 slot = upper_32_bits(range.bus_addr);
 
-               if (DT_FLAGS_TO_TYPE(range.flags) == DT_TYPE_IO)
-                       rtype = IORESOURCE_IO;
-               else if (DT_FLAGS_TO_TYPE(range.flags) == DT_TYPE_MEM32)
-                       rtype = IORESOURCE_MEM;
-               else
-                       continue;
-
-               if (slot == PCI_SLOT(devfn) && type == rtype) {
+               if (slot == PCI_SLOT(devfn) && type == range.flags) {
                        *tgt = DT_CPUADDR_TO_TARGET(range.cpu_addr);
                        *attr = DT_CPUADDR_TO_ATTR(range.cpu_addr);
                        return 0;