Re: [PATCH v6 11/12] lib/vsprintf: Add %pfw conversion specifier for printing fwnode names

Joe Perches
2019-09-10T10:21:32Z

On Tue, 2019-09-10 at 11:47 +0300, Sakari Ailus wrote:
> Add support for %pfw conversion specifier (with "f" and "P" modifiers) to
> support printing full path of the node, including its name ("f") and only
> the node's name ("P") in the printk family of functions. The two flags
> have equivalent functionality to existing %pOF with the same two modifiers
> ("f" and "P") on OF based systems. The ability to do the same on ACPI
> based systems is added by this patch.

checkpatch comment below:
A.
> diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst
[]
> @@ -418,6 +418,30 @@ Examples::
>
> Passed by reference.
>
> +Fwnode handles
> +--------------
> +
> +::
> +
> + %pfw[fP]
> +
> +For printing information on fwnode handles. The default is to print the full
> +node name, including the path. The modifiers are functionally equivalent to
> +%pOF above.
> +
> + - f - full name of the node, including the path
> + - P - the name of the node including an address (if there is one)
> +
> +Examples (ACPI)::
> +
> + %pfwf \_SB.PCI0.CIO2.port@1.endpoint@0 - Full node name
> + %pfwP endpoint@0 - Node name
> +
> +Examples (OF)::
> +
> + %pfwf /ocp@68000000/i2c@48072000/camera@10/port/endpoint - Full name
> + %pfwP endpoint - Node name
[]
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -5988,14 +5988,17 @@ sub process {
> for (my $count = $linenr; $count <= $lc; $count++) {
> my $specifier;
> my $extension;
> + my $qualifier;
> my $bad_specifier = "";
> my $fmt = get_quoted_string($lines[$count - 1], raw_line($count, 0));
> $fmt =~ s/%%//g;
>
> - while ($fmt =~ /(\%[\*\d\.]*p(\w))/g) {
> + while ($fmt =~ /(\%[\*\d\.]*p(\w)(\w?))/g) {

This is not generic enough to allow all possible qualifiers
to be captured.

This should be something like:

while ($fmt =~ /(\%[\*\d\.]*p(\w)(\w*))/g) {

> $specifier = $1;
> $extension = $2;
> - if ($extension !~ /[SsBKRraEhMmIiUDdgVCbGNOxt]/) {
> + $qualifier = $3;
> + if ($extension !~ /[SsBKRraEhMmIiUDdgVCbGNOxtf]/ ||
> + ($extension eq "f" && $qualifier ne "w")) {

And this should likely test
(defined $qualifier &&
$extension eq 'f' && $qualifier =~ /^w/))

> $bad_specifier = $specifier;
> last;
> }

And here the 'f' isn't really a bad $specifier,
it does not have the correct 'w' $extension.

The valid extensions may change in the future and
this code isn't particularly manageable, so I
think the $specifier/$extension pair should likely
have some additional testing after validating
the $specifier.