On Fri, Jul 17, 2020 at 03:37:42PM +0200, Hans de Goede wrote:
> In the not-enabled -> enabled path pwm_lpss_apply() needs to get a
> runtime-pm reference; and then on any errors it needs to release it
> again.
>
> This leads to somewhat hard to read code. This commit introduces a new
> pwm_lpss_prepare_enable() helper and moves all the steps necessary for
> the not-enabled -> enabled transition there, so that we can error check
> the entire transition in a single place and only have one pm_runtime_put()
> on failure call site.
>
> While working on this I noticed that the enabled -> enabled (update
> settings) path was quite similar, so I've added an enable parameter to
> the new pwm_lpss_prepare_enable() helper, which allows using it in that
> path too.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
But see below.
> Suggested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
> drivers/pwm/pwm-lpss.c | 45 ++++++++++++++++++++++++------------------
> 1 file changed, 26 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
> index da9bc3d10104..8a136ba2a583 100644
> --- a/drivers/pwm/pwm-lpss.c
> +++ b/drivers/pwm/pwm-lpss.c
> @@ -122,41 +122,48 @@ static inline void pwm_lpss_cond_enable(struct pwm_device *pwm, bool cond)
> pwm_lpss_write(pwm, pwm_lpss_read(pwm) | PWM_ENABLE);
> }
>
> +static int pwm_lpss_prepare_enable(struct pwm_lpss_chip *lpwm,
> + struct pwm_device *pwm,
> + const struct pwm_state *state,
> + bool enable)
> +{
> + int ret;
> +
> + ret = pwm_lpss_is_updating(pwm);
> + if (ret)
> + return ret;
> +
> + pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
> + pwm_lpss_cond_enable(pwm, enable && lpwm->info->bypass == false);
> + ret = pwm_lpss_wait_for_update(pwm);
> + if (ret)
> + return ret;
> +
> + pwm_lpss_cond_enable(pwm, enable && lpwm->info->bypass == true);
> + return 0;
> +}
> +
> static int pwm_lpss_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> const struct pwm_state *state)
> {
> struct pwm_lpss_chip *lpwm = to_lpwm(chip);
> - int ret;
> + int ret = 0;
We can avoid this change...
> if (state->enabled) {
> if (!pwm_is_enabled(pwm)) {
> pm_runtime_get_sync(chip->dev);
> - ret = pwm_lpss_is_updating(pwm);
> - if (ret) {
> - pm_runtime_put(chip->dev);
> - return ret;
> - }
> - pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
> - pwm_lpss_cond_enable(pwm, lpwm->info->bypass == false);
> - ret = pwm_lpss_wait_for_update(pwm);
> - if (ret) {
> + ret = pwm_lpss_prepare_enable(lpwm, pwm, state, true);
> + if (ret)
> pm_runtime_put(chip->dev);
> - return ret;
> - }
> - pwm_lpss_cond_enable(pwm, lpwm->info->bypass == true);
> } else {
> - ret = pwm_lpss_is_updating(pwm);
> - if (ret)
> - return ret;
> - pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
> - return pwm_lpss_wait_for_update(pwm);
> + ret = pwm_lpss_prepare_enable(lpwm, pwm, state, false);
...by simple return directly from here. But I admit I haven't seen the next patch yet.
> }
> } else if (pwm_is_enabled(pwm)) {
> pwm_lpss_write(pwm, pwm_lpss_read(pwm) & ~PWM_ENABLE);
> pm_runtime_put(chip->dev);
> }
>
> - return 0;
> + return ret;
> }
>
> static void pwm_lpss_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
> --
> 2.26.2
>
--
With Best Regards,
Andy Shevchenko
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