From c45fcf46ca2368dafe7e5c513a711a6f0f974308 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Fri, 21 Jun 2024 16:37:12 +0200 Subject: [PATCH] pwm: stm32: Refuse too small period requests MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If period_ns is small, prd might well become 0. Catch that case because otherwise with regmap_write(priv->regmap, TIM_ARR, prd - 1); a few lines down quite a big period is configured. Fixes: 7edf7369205b ("pwm: Add driver for STM32 plaftorm") Cc: stable@vger.kernel.org Reviewed-by: Trevor Gamblin Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/b86f62f099983646f97eeb6bfc0117bb2d0c340d.1718979150.git.u.kleine-koenig@baylibre.com Signed-off-by: Uwe Kleine-König --- drivers/pwm/pwm-stm32.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c index a2f231d13a9f..3e7b2a8e34e7 100644 --- a/drivers/pwm/pwm-stm32.c +++ b/drivers/pwm/pwm-stm32.c @@ -337,6 +337,8 @@ static int stm32_pwm_config(struct stm32_pwm *priv, unsigned int ch, prd = mul_u64_u64_div_u64(period_ns, clk_get_rate(priv->clk), (u64)NSEC_PER_SEC * (prescaler + 1)); + if (!prd) + return -EINVAL; /* * All channels share the same prescaler and counter so when two