From 9ee124caae1b0defd0e02c65686f539845a3ac9b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Fri, 4 Jul 2025 19:24:17 +0200 Subject: [PATCH 1/2] pwm: Fix invalid state detection MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit 9dd42d019e63 ("pwm: Allow pwm state transitions from an invalid state") intended to allow some state transitions that were not allowed before. The idea is sane and back then I also got the code comment right, but the check for enabled is bogus. This resulted in state transitions for enabled states to be allowed to have invalid duty/period settings and thus it can happen that low-level drivers get requests for invalid states🙄. Invert the check to allow state transitions for disabled states only. Fixes: 9dd42d019e63 ("pwm: Allow pwm state transitions from an invalid state") Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20250704172416.626433-2-u.kleine-koenig@baylibre.com Cc: stable@vger.kernel.org Signed-off-by: Uwe Kleine-König --- drivers/pwm/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 4d842c692194..edf776b8ad53 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -596,7 +596,7 @@ static bool pwm_state_valid(const struct pwm_state *state) * and supposed to be ignored. So also ignore any strange values and * consider the state ok. */ - if (state->enabled) + if (!state->enabled) return true; if (!state->period) From 505b730ede7f5c4083ff212aa955155b5b92e574 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Fri, 4 Jul 2025 19:27:27 +0200 Subject: [PATCH 2/2] pwm: mediatek: Ensure to disable clocks in error path MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit After enabling the clocks each error path must disable the clocks again. One of them failed to do so. Unify the error paths to use goto to make it harder for future changes to add a similar bug. Fixes: 7ca59947b5fc ("pwm: mediatek: Prevent divide-by-zero in pwm_mediatek_config()") Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20250704172728.626815-2-u.kleine-koenig@baylibre.com Cc: stable@vger.kernel.org Signed-off-by: Uwe Kleine-König --- drivers/pwm/pwm-mediatek.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c index 7eaab5831499..33d3554b9197 100644 --- a/drivers/pwm/pwm-mediatek.c +++ b/drivers/pwm/pwm-mediatek.c @@ -130,8 +130,10 @@ static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm, return ret; clk_rate = clk_get_rate(pc->clk_pwms[pwm->hwpwm]); - if (!clk_rate) - return -EINVAL; + if (!clk_rate) { + ret = -EINVAL; + goto out; + } /* Make sure we use the bus clock and not the 26MHz clock */ if (pc->soc->has_ck_26m_sel) @@ -150,9 +152,9 @@ static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm, } if (clkdiv > PWM_CLK_DIV_MAX) { - pwm_mediatek_clk_disable(chip, pwm); dev_err(pwmchip_parent(chip), "period of %d ns not supported\n", period_ns); - return -EINVAL; + ret = -EINVAL; + goto out; } if (pc->soc->pwm45_fixup && pwm->hwpwm > 2) { @@ -169,9 +171,10 @@ static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm, pwm_mediatek_writel(pc, pwm->hwpwm, reg_width, cnt_period); pwm_mediatek_writel(pc, pwm->hwpwm, reg_thres, cnt_duty); +out: pwm_mediatek_clk_disable(chip, pwm); - return 0; + return ret; } static int pwm_mediatek_enable(struct pwm_chip *chip, struct pwm_device *pwm)