Use of_get_cpu_hwid() rather than the open coded reading of the CPU
nodes "reg" property. The existing code is in fact wrong as the "reg"
address cells size is 2 cells for arm64. The existing code happens to
work because the DTS files are wrong as well.

Signed-off-by: Rob Herring <robh@kernel.org>
---
Note this should be marked for stable so that if/when the DTS files are
fixed, then at least stable kernels will work. This is untested, so I
didn't mark for stable.
---
 drivers/clk/mvebu/ap-cpu-clk.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/clk/mvebu/ap-cpu-clk.c b/drivers/clk/mvebu/ap-cpu-clk.c
index 71bdd7c3ff03..d8a7a4c90d54 100644
--- a/drivers/clk/mvebu/ap-cpu-clk.c
+++ b/drivers/clk/mvebu/ap-cpu-clk.c
@@ -253,12 +253,12 @@ static int ap_cpu_clock_probe(struct platform_device *pdev)
 	 */
 	nclusters = 1;
 	for_each_of_cpu_node(dn) {
-		int cpu, err;
+		u64 cpu;
 
-		err = of_property_read_u32(dn, "reg", &cpu);
-		if (WARN_ON(err)) {
+		cpu = of_get_cpu_hwid(dn, 0);
+		if (WARN_ON(cpu == OF_BAD_ADDR)) {
 			of_node_put(dn);
-			return err;
+			return -EINVAL;
 		}
 
 		/* If cpu2 or cpu3 is enabled */
@@ -288,12 +288,12 @@ static int ap_cpu_clock_probe(struct platform_device *pdev)
 		struct clk_init_data init;
 		const char *parent_name;
 		struct clk *parent;
-		int cpu, err;
+		u64 cpu;
 
-		err = of_property_read_u32(dn, "reg", &cpu);
-		if (WARN_ON(err)) {
+		cpu = of_get_cpu_hwid(dn, 0);
+		if (WARN_ON(cpu == OF_BAD_ADDR)) {
 			of_node_put(dn);
-			return err;
+			return -EINVAL;
 		}
 
 		cluster_index = cpu & APN806_CLUSTER_NUM_MASK;

-- 
2.39.2

Quoting Rob Herring (2023-03-27 11:43:19)
> Use of_get_cpu_hwid() rather than the open coded reading of the CPU
> nodes "reg" property. The existing code is in fact wrong as the "reg"
> address cells size is 2 cells for arm64. The existing code happens to
> work because the DTS files are wrong as well.
> 
> Signed-off-by: Rob Herring <robh@kernel.org>
> ---
> Note this should be marked for stable so that if/when the DTS files are
> fixed, then at least stable kernels will work. This is untested, so I
> didn't mark for stable.

That makes it sound like it breaks for existing DTS files. Is that the
case?

On Mon, Apr 10, 2023 at 04:36:21PM -0700, Stephen Boyd wrote:
> Quoting Rob Herring (2023-03-27 11:43:19)
> > Use of_get_cpu_hwid() rather than the open coded reading of the CPU
> > nodes "reg" property. The existing code is in fact wrong as the "reg"
> > address cells size is 2 cells for arm64. The existing code happens to
> > work because the DTS files are wrong as well.
> > 
> > Signed-off-by: Rob Herring <robh@kernel.org>
> > ---
> > Note this should be marked for stable so that if/when the DTS files are
> > fixed, then at least stable kernels will work. This is untested, so I
> > didn't mark for stable.
> 
> That makes it sound like it breaks for existing DTS files. Is that the
> case?

No, if the DTS files are fixed, then they will not work with the 
existing code. This change should work for both existing and fixed DTS 
files.

Rob