Re: [PATCH v2] checkpatch: DT bindings should be a separate patch

[Joe Perches]

On Fri, 2018-08-10 at 11:05 -0600, Rob Herring wrote:
> Devicetree bindings should be their own patch as documented in
> Documentation/devicetree/bindings/submitting-patches.txt section I.1.
> This is because bindings are logically independent from a driver
> implementation, they have a different maintainer (even though they often
> are applied via the same tree), and it makes for a cleaner history in
> the DT only tree created with git-filter-branch.
> 
> Cc: Andy Whitcroft <apw@xxxxxxxxxxxxx>
> Cc: Joe Perches <joe@xxxxxxxxxxx>
> Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
> ---
> v2:
> - Add doc pointer to warning
> - Simplify logic
> 
> Joe, this makes $is_binding_patch an empty value when the regex doesn't 
> match rather than 0 which would be more logical IMO. It seems to work 
> fine, but I'm not sure if there's a better way to do it.

Hi Rob.  This looks fine with a couple nits.

>  scripts/checkpatch.pl | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index a9c05506e325..f9aba4bc41ce 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -2236,6 +2236,7 @@ sub process {
>  	our $clean = 1;
>  	my $signoff = 0;
>  	my $is_patch = 0;
> +	my $is_binding_patch = -1;
>  	my $in_header_lines = $file ? 0 : 1;
>  	my $in_commit_log = 0;		#Scanning lines before patch
>  	my $has_commit_log = 0;		#Encountered lines before patch
> @@ -2485,6 +2486,19 @@ sub process {
>  				$check = $check_orig;
>  			}
>  			$checklicenseline = 1;
> +
> +			if ($realfile !~ /^MAINTAINERS/) {
> +				my $last_binding_patch = $is_binding_patch;
> +
> +				$is_binding_patch = ($realfile =~ m@^(?:Documentation/devicetree/|include/dt-bindings/)@);

If you want 0/1 you could use:

			$is_binding_patch = () = $realfile =~ m@^(?:Documentation/devicetree/|include/dt-bindings/)@;

(perl syntax is a constant joy)

> +
> +				if (($last_binding_patch != -1) &&
> +				    ($last_binding_patch ^ $is_binding_patch)) {
> +					WARN("DT_SPLIT_BINDING_PATCH",
> +					     "DT binding docs and includes should be a separate patch. See: Documentation/devicetree/bindings/submitting-patches.txt");

This is missing a '\n' newline at the end of the message.

> +				}
> +			}
> +
>  			next;
>  		}
>