On Tue, Nov 09, 2021 at 10:46:49AM -0600, Rob Herring wrote:
> Commit 25b892b583cc ("ARM: dts: arm: Update register-bit-led nodes
> 'reg' and node names") added a 'reg' property to nodes. This change has
> the side effect of changing how the kernel generates the device name.
> The assumption was a translatable 'reg' address is unique. However, in
> the case of the register-bit-led binding (and a few others) that is not
> the case. The 'mask' property must also be used in this case to make a
> unique device name.
>
> Fixes: 25b892b583cc ("ARM: dts: arm: Update register-bit-led nodes 'reg' and node names")
> Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Frank Rowand <frowand.list@xxxxxxxxx>
> Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
> Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> ---
> This should be applied to stable to minimize DT ABI breakage.
> ---
> drivers/of/platform.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index 07813fb1ef37..b3faf89744aa 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -76,6 +76,7 @@ static void of_device_make_bus_id(struct device *dev)
> struct device_node *node = dev->of_node;
> const __be32 *reg;
> u64 addr;
> + u32 mask;
>
> /* Construct the name, using parent nodes if necessary to ensure uniqueness */
> while (node->parent) {
> @@ -85,8 +86,13 @@ static void of_device_make_bus_id(struct device *dev)
> */
> reg = of_get_property(node, "reg", NULL);
> if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
> - dev_set_name(dev, dev_name(dev) ? "%llx.%pOFn:%s" : "%llx.%pOFn",
> - addr, node, dev_name(dev));
> + if (!of_property_read_u32(node, "mask", &mask))
> + dev_set_name(dev, dev_name(dev) ? "%llx.%x.%pOFn:%s" : "%llx.%x.%pOFn",
> + addr, ffs(mask) - 1, node, dev_name(dev));
> +
> + else
> + dev_set_name(dev, dev_name(dev) ? "%llx.%pOFn:%s" : "%llx.%pOFn",
> + addr, node, dev_name(dev));
> return;
> }
>
> --
> 2.32.0
>
