[PATCH 5/5] pwm: stm32: Fix enable count for clk in .probe()

[Uwe Kleine-König]

Hello Fabrice,

On Wed, Nov 15, 2023 at 10:02:20AM +0100, Fabrice Gasnier wrote:
> (with or without a Fixes tag) Could you add a check on global counter
> enable bit (TIM_CR1_CEN) both in the .get_state(), and in the
> stm32_pwm_detect_channels(), that counts the num_enabled channels ?

I'd address that separately, mostly because the patches forwarded here
are not mine.

> In case the TIM_CR1_CEN isn't set (but some of the TIM_CCER_CCXE are),
> the driver will report enabled channels. But physically, the pwm output
> will be inactive.

Huuu, that means if channel #0 is running and I start a capture on
channel #1 which results in unconditionally calling
regmap_clear_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN); (in
stm32_pwm_raw_capture()) channel #0 stops to toggle!

> That's more a robustness case... depending on what's been done possibly
> by bootloader. What to you think ?

I would assume that a bootloader that sets the CCXE bits also enables
TIM_CR1_CEN and so in practise Philipp's patch is fine. But I agree that
doing things properly would be better.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 488 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20231115/1ddd29a1/attachment.sig>