[PATCH v2] cmd: clk: probe the clock before dump them

[Patrick Delaunay]

The clock UCLASS need to be probed to allow availability of the
private data (struct clk *), get in show_clks() with dev_get_clk_ptr()
before use them.

Without this patch the clock dump can cause crash because all the
private data are not available before calling the API clk_get_rate().

It is the case for the SCMI clocks, priv->channel is needed for
scmi_clk_get_rate() and it is initialized only in scmi_clk_probe().
This issue causes a crash for "clk dump" command on STM32MP135F-DK board
for SCMI clock not yet probed.

Fixes: 1a725e229096 ("clk: fix clock tree dump to properly dump out every registered clock")
Signed-off-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
---

Changes in v2:
- simplify the patch after Simon review of V1: always probe the clk device
  before call to show_clks(), by using device_foreach_child_probe() and
  uclass_foreach_dev_probe()
- test UCLASS_CLK only when show_clks is called for child device

 cmd/clk.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/cmd/clk.c b/cmd/clk.c
index a483fd898122..ff7c7649a159 100644
--- a/cmd/clk.c
+++ b/cmd/clk.c
@@ -22,7 +22,7 @@ static void show_clks(struct udevice *dev, int depth, int last_flag)
 	u32 rate;
 
 	clkp = dev_get_clk_ptr(dev);
-	if (device_get_uclass_id(dev) == UCLASS_CLK && clkp) {
+	if (clkp) {
 		parent = clk_get_parent(clkp);
 		if (!IS_ERR(parent) && depth == -1)
 			return;
@@ -49,10 +49,11 @@ static void show_clks(struct udevice *dev, int depth, int last_flag)
 		printf("%s\n", dev->name);
 	}
 
-	list_for_each_entry(child, &dev->child_head, sibling_node) {
+	device_foreach_child_probe(child, dev) {
+		if (device_get_uclass_id(child) != UCLASS_CLK)
+			continue;
 		if (child == dev)
 			continue;
-
 		is_last = list_is_last(&child->sibling_node, &dev->child_head);
 		show_clks(child, depth, (last_flag << 1) | is_last);
 	}
@@ -61,17 +62,11 @@ static void show_clks(struct udevice *dev, int depth, int last_flag)
 int __weak soc_clk_dump(void)
 {
 	struct udevice *dev;
-	struct uclass *uc;
-	int ret;
-
-	ret = uclass_get(UCLASS_CLK, &uc);
-	if (ret)
-		return ret;
 
 	printf(" Rate               Usecnt      Name\n");
 	printf("------------------------------------------\n");
 
-	uclass_foreach_dev(dev, uc)
+	uclass_foreach_dev_probe(UCLASS_CLK, dev)
 		show_clks(dev, -1, 0);
 
 	return 0;
-- 
2.25.1