Re: [RESEND PATCH v2] mfd: syscon: Use a unique name with regmap_config

From: Suman Anna
Date: Tue Jul 28 2020 - 11:35:08 EST

On 7/28/20 2:44 AM, Arnd Bergmann wrote:
On Mon, Jul 27, 2020 at 11:10 PM Suman Anna <s-anna@xxxxxx> wrote:

The DT node full name is currently being used in regmap_config
which in turn is used to create the regmap debugfs directories.
This name however is not guaranteed to be unique and the regmap
debugfs registration can fail in the cases where the syscon nodes
have the same unit-address but are present in different DT node
hierarchies. Replace this logic using the syscon reg resource
address instead (inspired from logic used while creating platform
devices) to ensure a unique name is given for each syscon.

Signed-off-by: Suman Anna <s-anna@xxxxxx>
Hi Arnd,
Lee is looking for your review on this patch. Can you please
review and provide your comments.

Sorry for missing this earlier. I think this makes sense, and I don't
expect the name change to cause problems, so

Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>

Thanks Arnd.

--- a/drivers/mfd/syscon.c
+++ b/drivers/mfd/syscon.c
@@ -101,12 +101,14 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)

- = of_node_full_name(np);
+ = kasprintf(GFP_KERNEL, "%pOFn@%llx", np,
+ (u64)res.start);

Note that you could avoid the cast by using "%pOFn@%pa", and
passing res.start by reference. Not important though, the result should
be similar, and you might not like the '0x' that this adds.

Yeah, preference was not to add the leading 0x or any leading 0s. We did discuss about this on the original v2 submission [1].