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| author | Uwe Kleine-König <u.kleine-koenig@baylibre.com> | 2024-07-03 13:00:06 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-08-03 08:48:55 +0200 |
| commit | 1d78d9625205a6f2d4d5841b87268b52e114a601 (patch) | |
| tree | 1bf32aa11f698409d31212f878253c5e569d7239 /drivers | |
| parent | 08085940c4bd7b1e9e0b68069914afcb245e5984 (diff) | |
| download | linux-1d78d9625205a6f2d4d5841b87268b52e114a601.tar.gz linux-1d78d9625205a6f2d4d5841b87268b52e114a601.tar.bz2 linux-1d78d9625205a6f2d4d5841b87268b52e114a601.zip | |
pwm: stm32: Always do lazy disabling
[ Upstream commit 7346e7a058a2c9aa9ff1cc699c7bf18a402d9f84 ]
When the state changes from enabled to disabled, polarity, duty_cycle
and period are not configured in hardware and TIM_CCER_CCxE is just
cleared. However if the state changes from one disabled state to
another, all parameters are written to hardware because the early exit
from stm32_pwm_apply() is only taken if the pwm is currently enabled.
This yields surprises like: Applying
{ .period = 1, .duty_cycle = 0, .enabled = false }
succeeds if the pwm is initially on, but fails if it's already off
because 1 is a too small period.
Update the check for lazy disable to always exit early if the target
state is disabled, no matter what is currently configured.
Fixes: 7edf7369205b ("pwm: Add driver for STM32 plaftorm")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20240703110010.672654-2-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/pwm/pwm-stm32.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c index c40a6548ce7d..2070d107c632 100644 --- a/drivers/pwm/pwm-stm32.c +++ b/drivers/pwm/pwm-stm32.c @@ -452,8 +452,9 @@ static int stm32_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, enabled = pwm->state.enabled; - if (enabled && !state->enabled) { - stm32_pwm_disable(priv, pwm->hwpwm); + if (!state->enabled) { + if (enabled) + stm32_pwm_disable(priv, pwm->hwpwm); return 0; } |