On Mon, Apr 24, 2023 at 07:44:02AM +0200, Uwe Kleine-König wrote:
> [ Upstream commit 8caa81eb950cb2e9d2d6959b37d853162d197f57 ]
>
> The driver only supports normal polarity. Complete the implementation of
> .get_state() by setting .polarity accordingly.
>
> This fixes a regression that was possible since commit c73a3107624d
> ("pwm: Handle .get_state() failures") which stopped to zero-initialize
> the state passed to the .get_state() callback. This was reported at
> https://forum.odroid.com/viewtopic.php?f=177&t=46360 . While this was an
> unintended side effect, the real issue is the driver's callback not
> setting the polarity.
>
> There is a complicating fact, that the .apply() callback fakes support
> for inversed polarity. This is not (and cannot) be matched by
> .get_state(). As fixing this isn't easy, only point it out in a comment
> to prevent authors of other drivers from copying that approach.
>
> Fixes: c375bcbaabdb ("pwm: meson: Read the full hardware state in meson_pwm_get_state()")
> Reported-by: Munehisa Kamata <kamatam@xxxxxxxxxx>
> Acked-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
> Link: https://lore.kernel.org/r/20230310191405.2606296-1-u.kleine-koenig@xxxxxxxxxxxxxx
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
> Signed-off-by: Thierry Reding <thierry.reding@xxxxxxxxx>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
> ---
> On Sat, Apr 22, 2023 at 05:32:33PM +0200, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
> > @@ -304,6 +310,8 @@ static int meson_pwm_apply(struct pwm_ch
> > meson_pwm_enable(meson, pwm);
> > }
> >
> > + state->polarity = PWM_POLARITY_NORMAL;
> > +
>
> This is the wrong function this line was added, see also
> https://lore.kernel.org/stable/CA+G9fYuZdBJx8jF2STHzRZ8dw86awZ68OQen6bzgB=H+Z-tPAQ@xxxxxxxxxxxxxx
>
> Fixed patch below.
Thanks for the fixup, now queued up, along with the other backports.
greg k-h
