This is a note to let you know that I've just added the patch titled
pwm: stm32: Refuse too small period requests
to the 6.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pwm-stm32-refuse-too-small-period-requests.patch
and it can be found in the queue-6.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit cdf1762592f778dbfec99a8f9c9cc6740b4ffc94
Author: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxx>
Date: Fri Jun 21 16:37:12 2024 +0200
pwm: stm32: Refuse too small period requests
[ Upstream commit c45fcf46ca2368dafe7e5c513a711a6f0f974308 ]
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@xxxxxxxxxxxxxxx
Reviewed-by: Trevor Gamblin <tgamblin@xxxxxxxxxxxx>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/b86f62f099983646f97eeb6bfc0117bb2d0c340d.1718979150.git.u.kleine-koenig@xxxxxxxxxxxx
Signed-off-by: Uwe Kleine-König <ukleinek@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c
index 1c8911353b81d..a8a1075f932df 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
