Re: [PATCH 00/20] Simplify of_property_for_each_u32()

Hello Rob,

On Wed, 3 Jul 2024 12:07:42 -0600
Rob Herring [off-list ref] wrote:

On Wed, Jul 03, 2024 at 12:36:44PM +0200, Luca Ceresoli wrote:

quoted

[Note: to reduce the noise I have trimmed the get_maintainers list
manually. Should you want to be removed, or someone else added, to future
versions, just tell me. Sorry for the noise.]

This series aims at simplifying of_property_for_each_u32() as well as
making it more difficult to misuse it in the future.

The long-term goal is changing this pattern:

  struct property *prop;
  const __be32 *p;
  u32 val;
 
  of_property_for_each_u32(np, "xyz", prop, p, val) { ... }

to this:

  u32 val;

  of_property_for_each_u32(np, "xyz", val) { ... }

So, removing the 3rd and 4th arguments which are typically meant to be
internal. Those two parameters used to be unavoidable until the kernel
moved to building with the C11 standard unconditionally. Since then, it is
now possible to get rid of them. However a few users of
of_property_for_each_u32() do actually use those arguments, which
complicates the transition. For this reason this series does the following:

 * Add of_property_for_each_u32_new(), which does not have those two
   arguments (patch 1)
 * Convert _almost_ every usage to of_property_for_each_u32_new()
 * Rename of_property_for_each_u32() to of_property_for_each_u32_old() and
   deprecate it, as a incentive to code not (yet) in mainline to upgrade
   to the *_new() version (last patch)  

I don't really see the point of introducing the _old variant. Let's get 
this done in one step.

quoted

The plan for the next series is to additionally:

 * Convert the few remaining of_property_for_each_u32_old() instantes to
   of_property_for_each_u32_new()
 * Remove of_property_for_each_u32_old()
 * Rename of_property_for_each_u32_new() to of_property_for_each_u32()  

Honestly, I think there's few enough users we could just convert the 
whole thing in one patch. It's all got to go thru 1 tree anyways. If 
there's new cases in -next, then I'd be happy to send it to Linus at the 
end of the merge window.

Sure, make sense. I'll need to convert the few remaining users, then
I'm sending a squashed v2.

Luca

-- 
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com