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

[Sean Anderson]

On 12/13/22 08:57, Patrick Delaunay wrote:
> 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;

Reviewed-by: Sean Anderson <seanga2 at gmail.com>