Re: [PATCH v2 5/7] of/fdt: Simplify the logic of early_init_dt_scan_memory()

Rob Herring
2025-11-13T22:03:57Z

On Thu, Nov 13, 2025 at 11:51:02PM +0800, Yuntao Wang wrote:
> Use the existing helper functions to simplify the logic of
> early_init_dt_scan_memory()
>
> Signed-off-by: Yuntao Wang <yuntao.wang@linux.dev>
> ---
> drivers/of/fdt.c | 14 ++++++--------
> 1 file changed, 6 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> index 4c45a97d6652..b6b059960fc2 100644
> --- a/drivers/of/fdt.c
> +++ b/drivers/of/fdt.c
> @@ -1027,7 +1027,7 @@ int __init early_init_dt_scan_memory(void)
>
> fdt_for_each_subnode(node, fdt, 0) {
> const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
> - const __be32 *reg, *endp;
> + const __be32 *reg;
> int l;
> bool hotpluggable;
>
> @@ -1038,23 +1038,21 @@ int __init early_init_dt_scan_memory(void)
> if (!of_fdt_device_is_available(fdt, node))
> continue;
>
> - reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
> + reg = of_fdt_get_addr_size_prop(node, "linux,usable-memory", &l);
> if (reg == NULL)
> - reg = of_get_flat_dt_prop(node, "reg", &l);
> + reg = of_fdt_get_addr_size_prop(node, "reg", &l);
> if (reg == NULL)
> continue;
>
> - endp = reg + (l / sizeof(__be32));
> hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
>
> - pr_debug("memory scan node %s, reg size %d,\n",
> + pr_debug("memory scan node %s, reg {addr,size} entries %d,\n",
> fdt_get_name(fdt, node, NULL), l);
>
> - while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
> + while (l-- > 0) {
> u64 base, size;
>
> - base = dt_mem_next_cell(dt_root_addr_cells, &reg);
> - size = dt_mem_next_cell(dt_root_size_cells, &reg);
> + of_fdt_read_addr_size(reg, &base, &size);

This doesn't work. of_fdt_read_addr_size() needs to take an entry index
to read each entry.

Rob