Re: [libgpiod][PATCH] bindings: python: fix LineRequest.set_value only works for the last entry

[Bartosz Golaszewski <brgl@xxxxxxxx>]

On Tue, Jun 25, 2024 at 3:25 AM <chuang+git@xxxxxxxxxx> wrote:
>
> From: Chuang Zhu <git@xxxxxxxxx>
>
> When multiple entries are requested using line names in
> Chip.request_lines, only the the last entry is added to
> LineRequest._name_map, causing a ValueError when trying to use
> LineRequest.set_value on any former entries.
>
> >>> import gpiod
> >>> lr = gpiod.Chip('/dev/gpiochip0').request_lines(
> ...     config={
> ...         'LINE0': gpiod.LineSettings(direction=gpiod.line.Direction.OUTPUT,
> ...                                     output_value=gpiod.line.Value.INACTIVE),
> ...         'LINE2': gpiod.LineSettings(direction=gpiod.line.Direction.OUTPUT, active_low=True,
> ...                                     output_value=gpiod.line.Value.ACTIVE),
> ...     }
> ... )
> >>> lr._name_map
> {'LINE2': 2}
> >>> lr.set_value('LINE0', gpiod.line.Value.ACTIVE)
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
>   File ".../gpiod/line_request.py", line 126, in set_value
>     self.set_values({line: value})
>   File ".../gpiod/line_request.py", line 138, in set_values
>     mapped = {
>              ^
>   File ".../gpiod/line_request.py", line 139, in <dictcomp>
>     self._name_map[line] if self._check_line_name(line) else line: values[line]
>                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^
>   File ".../gpiod/line_request.py", line 82, in _check_line_name
>     raise ValueError("unknown line name: {}".format(line))
> ValueError: unknown line name: LINE0
>
> Signed-off-by: Chuang Zhu <git@xxxxxxxxx>
> ---
>  bindings/python/gpiod/chip.py | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/bindings/python/gpiod/chip.py b/bindings/python/gpiod/chip.py
> index b3d8e61..ce77d27 100644
> --- a/bindings/python/gpiod/chip.py
> +++ b/bindings/python/gpiod/chip.py
> @@ -279,11 +279,12 @@ class Chip:
>          else:
>              mapped_output_values = None
>
> +        offsets = list()
> +        name_map = dict()
> +        offset_map = dict()
> +        global_output_values = list()
> +
>          for lines, settings in config.items():
> -            offsets = list()
> -            name_map = dict()
> -            offset_map = dict()
> -            global_output_values = list()
>
>              if isinstance(lines, int) or isinstance(lines, str):
>                  lines = (lines,)
> --
> 2.44.0
>
>

Thanks! Please rework the commit message as advised by Kent.
Especially: explain what effect the changes have.

Bart