From: Thierry Reding thierry.reding@gmail.com
[ Upstream commit 6eefb79d6f5bc4086bd02c76f1072dd4a8d9d9f6 ]
Commit d3817a647059 ("pwm: sun4i: Remove redundant needs_delay") changed the logic of an else branch so that the PWM_EN and PWM_CLK_GATING bits are now cleared if the PWM is to be disabled, whereas previously the condition was always false, and hence the branch never got executed.
This code is reported causing backlight issues on boards based on the Allwinner A20 SoC. Fix this by removing the else branch, which restores the behaviour prior to the offending commit.
Note that the PWM_EN and PWM_CLK_GATING bits still get cleared later in sun4i_pwm_apply() if the PWM is to be disabled.
Fixes: d3817a647059 ("pwm: sun4i: Remove redundant needs_delay") Reported-by: Taras Galchenko tpgalchenko@gmail.com Suggested-by: Taras Galchenko tpgalchenko@gmail.com Tested-by: Taras Galchenko tpgalchenko@gmail.com Reviewed-by: Uwe Kleine-König u.kleine-koenig@pengutronix.de Signed-off-by: Thierry Reding thierry.reding@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pwm/pwm-sun4i.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c index 38a4c5c1317b2..482d5b9cec1fb 100644 --- a/drivers/pwm/pwm-sun4i.c +++ b/drivers/pwm/pwm-sun4i.c @@ -294,12 +294,8 @@ static int sun4i_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
ctrl |= BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
- if (state->enabled) { + if (state->enabled) ctrl |= BIT_CH(PWM_EN, pwm->hwpwm); - } else { - ctrl &= ~BIT_CH(PWM_EN, pwm->hwpwm); - ctrl &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm); - }
sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG);